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组分距离方法构建基于核糖体蛋白质或氨酰tRNA合成酶的原核生物亲缘树 被引量:4
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作者 卫海滨 戚继 郝柏林 《中国科学(C辑)》 CSCD 北大核心 2004年第2期186-194,共9页
最近新发展的基于计算短串频度,推断原核生物系统发生关系的K串组分距离方法,以整个蛋白质组作为数据集.采用每个物种的全部核糖体蛋白质或氨酰tRNA合成酶,得到一致结果.已知后一组蛋白质在单个使用时,产生彼此不同的进化树.我们构建进... 最近新发展的基于计算短串频度,推断原核生物系统发生关系的K串组分距离方法,以整个蛋白质组作为数据集.采用每个物种的全部核糖体蛋白质或氨酰tRNA合成酶,得到一致结果.已知后一组蛋白质在单个使用时,产生彼此不同的进化树.我们构建进化树不需做任何序列联配,所得亲缘树包括16个古细菌、105个细菌和2个真核生物.大部分低层分支与《伯杰系统细菌学手册》(第2版),即2003年第4次发布的细菌系统分类大纲相一致,而且对高层分支关系给出一些建议. 展开更多
关键词 古细菌 系统发生树 组分距离 核糖体蛋白质 氨酰TRNA合成酶 原核生物亲缘树
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The St.George's Respiratory Questionnaire in Lymphangioleiomyomatosis 被引量:1
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作者 Kai-feng Xu LanWang Xin-lun Tian Yao-song Gui Min Peng Bai-qiang Cai Yuan-jue Zhu 《Chinese Medical Sciences Journal》 CAS CSCD 2010年第3期140-145,共6页
Objective To examine the correlation between the health-related quality of life measured by the St.George's Respiratory Questionnaire(SGRQ) and the commonly used physiological measures in lymphangioleiomyomatosis(... Objective To examine the correlation between the health-related quality of life measured by the St.George's Respiratory Questionnaire(SGRQ) and the commonly used physiological measures in lymphangioleiomyomatosis(LAM).Methods This study retrospectively analyzed the SGRQ scores and other measures(the Borg scale of breathlessness at rest,6-minute walking distance,blood oxygen levels,and pulmonary function) of patients diagnosed and confirmed with LAM.Altogether 38 patients between June 2007 and November 2009 were included.Results The mean values of the SGRQ three components(symptoms,activity,and impacts) and total scores in the LAM patients were 46.95±28.90,58.47±25.41,47.89±29.66,and 51.11±26.35,respectively.The SGRQ total or component scores were correlated well with the Borg scale of breathlessness,6-minute walking distance,partial pressure of oxygen in arterial blood,spirometry and diffusion capacity of lung.There were poor correlations between SGRQ score and residual volume or total lung capacity.In our preliminary observation,sirolimus improved the SGRQ total and three component scores and the Borg scale of breathlessness significantly after 101-200 days of treatment(n=6).Conclusions The SGRQ score in LAM is correlated well with physiological measures(Borg scale of breathlessness,6-minute walking distance,blood oxygen levels,and pulmonary function tests).The SGRQ could therefore be recommended in baseline and follow-up evaluation of patients with LAM.Treatment with sirolimus,an inhibitor of mammalian target of rapamycin,may improve the quality of life and patient's perception of breathlessness in LAM. 展开更多
关键词 LYMPHANGIOLEIOMYOMATOSIS St. George's Respiratory Questionnaire pulmonary function quality of life SIROLIMUS
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A Combinational Power Analysis Method against Cryptographic Hardware
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作者 GUO Zheng GU Dawu +4 位作者 LU Haining LIU Junrong XU Sen BAO Sigang GU Haihua 《China Communications》 SCIE CSCD 2015年第1期99-107,共9页
Power analysis is a non-invaslve attack against cryptographic hardware, which effectively exploits runtime power consumption characteristics of circuits. This paper proposes a new power model which combines Hamming Di... Power analysis is a non-invaslve attack against cryptographic hardware, which effectively exploits runtime power consumption characteristics of circuits. This paper proposes a new power model which combines Hamming Distance model and the model based on the template value of power consumption in combinational logic circuit. The new model can describe the power consumption characteristics of sequential logic circuits and those of combinational logic as well. The new model can be used to improve the existing power analysis methods and detect the information leakage of power consumption. Experimental results show that, compared to CPA(Correlation Power Analysis) method, our proposed attack which adopt the combinational model is more efficient in terms of the number of required power traces. 展开更多
关键词 cryptographic hardware side channel attack power analysis combinational logic
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Kondo Effect Versus Magnetic Coupling in Indirectly Coupled Double Quantum Dots
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作者 龙文 孙庆丰 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第11期933-937,共5页
We theoretically investigate a device consisting of two quantum dots (QDs) side-coupled to a quantum wire which has many physical ingredients of an artificial heavy fermion system. An extra parameter, the distance L... We theoretically investigate a device consisting of two quantum dots (QDs) side-coupled to a quantum wire which has many physical ingredients of an artificial heavy fermion system. An extra parameter, the distance L between the two QDs, is introduced and it plays an important role on the competition of the Kondo temperature and magnetic coupling. Three different phases are found: antiferromagnetic phase, Kondo phase with spin S = 1/2, and Kondo phase with S = 1, depending on the distance L, the magnetic properties are qualitatively different for different phases: conductance tends to the unitary value 2e2 /h; for the S : the distance. coupling, and the Kondo temperature. Quantum transport for the S = 1 Kondo and the antiferromagnetic phases, the 1/2 Kondo phase the conductance is strongly dependent onthe distance. 展开更多
关键词 quantum dot Kondo effect RKKY interaction
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冠状病毒和人类SARS病毒的分子亲缘关系研究 被引量:5
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作者 高雷 戚继 +2 位作者 卫海滨 孙奕钢 郝柏林 《科学通报》 EI CAS CSCD 北大核心 2003年第12期1246-1250,共5页
组分矢量方法是一种从全基因组出发,研究物种亲缘关系的新方法。本文使用这一方法,通过对外类群的适当选取,研究包括SARS病毒的冠状病毒进化关系。SARS病毒作为一个单系,由于彼此之间的序列相似程度非常高,难以为其选取适当的外类群。... 组分矢量方法是一种从全基因组出发,研究物种亲缘关系的新方法。本文使用这一方法,通过对外类群的适当选取,研究包括SARS病毒的冠状病毒进化关系。SARS病毒作为一个单系,由于彼此之间的序列相似程度非常高,难以为其选取适当的外类群。我们利用核苷酸的突变计数来构造距离矩阵,并将其超度规化,在此基础上揭示SARS病毒自身的演变关系。本文采用了更多的序列和新的方法,反映了更为详细的冠状病毒进化关系,使得不同方法的比较成为可能,为冠状病毒进化关系的研究提供了新的视角。 展开更多
关键词 冠状病毒 SARS病毒 分子亲缘关系 严重急性呼吸综合征 分子进化 组分距离 超度规
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Self-organizing dual clustering considering spatial analysis and hybrid distance measures 被引量:10
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作者 JIAO LiMin LIU YaoLin ZOU Bin 《Science China Earth Sciences》 SCIE EI CAS 2011年第8期1268-1278,共11页
Dual clustering performs object clustering in both spatial and non-spatial domains that cannot be dealt with well by traditional clustering methods.However,recent dual clustering research has often omitted spatial out... Dual clustering performs object clustering in both spatial and non-spatial domains that cannot be dealt with well by traditional clustering methods.However,recent dual clustering research has often omitted spatial outliers,subjectively determined the weights of hybrid distance measures,and produced diverse clustering results.In this study,we first redefined the dual clustering problem and related concepts to highlight the clustering criteria.We then presented a self-organizing dual clustering algorithm (SDC) based on the self-organizing feature map and certain spatial analysis operations,including the Voronoi diagram and polygon aggregation and amalgamation.The algorithm employs a hybrid distance measure that combines geometric distance and non-spatial similarity,while the clustering spectrum analysis helps to determine the weight of non-spatial similarity in the measure.A case study was conducted on a spatial database of urban land price samples in Wuhan,China.SDC detected spatial outliers and clustered the points into spatially connective and attributively homogenous sub-groups.In particular,SDC revealed zonal areas that describe the actual distribution of land prices but were not demonstrated by other methods.SDC reduced the subjectivity in dual clustering. 展开更多
关键词 dual clustering DATAMINING self-organizing feature map Voronoi diagram
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