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On the Caginalp for a Conserve Phase-Field with a Polynomial Potentiel of Order 2<i>p</i>- 1 认领
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作者 Narcisse Batangouna Cyr Séraphin Ngamouyih Moussata Urbain Cyriaque Mavoungou 《应用数学与应用物理(英文)》 2020年第12期2744-2756,共13页
Our aim in this paper is to study on the Caginalp for a conserved phase-field with a polynomial potentiel of order 2<em>p</em> - 1. In this part, one treats the conservative version of the problem of gener... Our aim in this paper is to study on the Caginalp for a conserved phase-field with a polynomial potentiel of order 2<em>p</em> - 1. In this part, one treats the conservative version of the problem of generalized phase field. We consider a regular potential, more precisely a polynomial term of the order 2<em>p</em> - 1 with edge conditions of Dirichlet type. Existence and uniqueness are analyzed. More precisely, we precisely, we prove the existence and uniqueness of solutions. 展开更多
关键词 A Conserved Phase-Field Polynomial Potentiel of Order 2p - 1 Dirichlet Boundary Conditions Maxwell-Cattaneo Law
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A Neumann System of the Third Order Differential Operator Associated with the Boussinesq Equation 认领
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作者 Jianli Cao Jingfang Han 《应用数学与应用物理(英文)》 2020年第12期2861-2868,共8页
Finite-dimensional integrable Hamiltonian system, obtained through the nonlinearization of the 3 × 3 spectral problem associated with the Boussinesq equation, is investigated. A generating function method startin... Finite-dimensional integrable Hamiltonian system, obtained through the nonlinearization of the 3 × 3 spectral problem associated with the Boussinesq equation, is investigated. A generating function method starting from the Lax-Moser matrix is used to give an effective way to prove the involutivity of integrals. Finite-parameter solution of the Boussinesq equation is calculated based on the commutative system of ordinary differential equations with these integrals as Hamiltonians. The problem of the third order differential operator associated with the Boussinesq Neumann system put forward by H. Flaschka in 1983 is solved. 展开更多
关键词 Boussinesq Equation Conserved Integrals Lax-Moser Matrix
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COVID-2019 Genome Sequence Analysis: Phylogenetic Molecular Evolution and Docking of Structural Modelling of Receptor Binding Domain of S Protein in Active Site of ACE2 认领
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作者 Abaysew Ayele Baba Abdissa +2 位作者 Dereje Taye Bereket Yemane Rita Singh Majumdar 《计算分子生物学(英文)》 2020年第3期95-110,共16页
Meanwhile the outbreak of the Covid-19 since December, 2019 in China, it has killed more than a hundred thousand of people of all ages and sex across the globe in a short span of time. On the bases of this study the n... Meanwhile the outbreak of the Covid-19 since December, 2019 in China, it has killed more than a hundred thousand of people of all ages and sex across the globe in a short span of time. On the bases of this study the nearest family member of the virus and its receptor binding domain of S protein including its model structure and function of its active sites were naked through Multiple Sequence Alignment, modelling and molecular docking software accordingly its repository genome databases. The virus was genetically associated and molecular evolutionary related with (<em>RaTG</em>13) and it scores 96.12% homology with 99% query coverage followed by <em>bat-SL-CoVZC</em>45 and<em> bat-SL-CoVZXC</em>21 notch 89.12% and 88.65% respectively. However, SARS and MERS corona type virus those outbreak earlier respectively less likely family members of 2019-nCoV. Though the virus has a close genetic association with those previous SARS coronaviruses, and certainly the spike protein used as a binding receptor to fight against human receptor protein of ACE 2, but on the basis of FRODOC and HDOCK server analysis multi favorable active sites of S protein was discovered such GLN493 shown as a finest key in both model and possessed a unique traits on it resulting unexpected rate of transmission and number of people died while compared to the previous one. TYR500, ASN501, GLN498 and others residues preferably contemplate site also. In particular, the diversity of the virus in the world may be due to the genome structure of the virus and S gene changed over the time, across the world against to host of human genetic diversity, which may be more robust, and may be a new and unique feature. This is because it is characterized close to contact with distance divergence between wild type novel coronavirus which was risen from China against to the genomes from Lebanon, India, Italy, and USA and so on. Thus, the World Health Organization and its researchers should focus on immunologic research and effective drug and vaccine development that 展开更多
关键词 MSA Phylogenetic Construct Genome Seq RBD Conserved Gene ACE2 S Spike Protein Genetic Mutation and Protein-Protein Docking
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Conserved Immunoglobulin Domain Similarities of Higher Plant Proteins 认领
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作者 Jaroslav Kubrycht Karel Sigler 《计算分子生物学(英文)》 2020年第1期12-44,共33页
The traces of immunoglobulin domain similarities were searched in sequences of higher plants using bioinformatic tools to look for possible early phylogenic structural relationships. 280 thousand sequence IDs, obtaine... The traces of immunoglobulin domain similarities were searched in sequences of higher plants using bioinformatic tools to look for possible early phylogenic structural relationships. 280 thousand sequence IDs, obtained by sixteen types of primary BLAST searches, were differently processed by seventeen selection procedures and an anti-redundant sequence-related approach using JavaScript, PHP, Windows programs and conserved domain searches by means CDD. The resulting seventeen sets of records describing conserved domain similarities of 1323 different sequence IDs yielded a set of next generation (final set) comprising forty-nine records containing superior (“non-refutable”) conserved immunoglobulin domain similarities. The selected sets and their subsets were mapped and subsequently statistically compared with respect to immunoglobulin-related as well as other reciprocal domain linkages. The list of frequently occurring conserved domain similarities concerned first of all domains important for plant and metazoan immunity, e.g. tyrosine kinases accompanying variable immunoglobulin domains in early Metazoa, toll-like receptors, lectin and leucine-rich repeat domains. Detailed description of immunoglobulin domain similarities occurring in the final set was completed by fold analysis of the restricted segments. The data were then discussed with respect to i) immunoglobulin fold evolution, ii) possible structural importance of domains cd14066 (IRAK) and PLN00113 (LRR-associated kinase) for deep evolution of catalytic serine/threonine/tyrosine kinase domains, iii) interatomic, structural and specificity standpoints and iv) traces of antibody-like phosphorylation sites described in our previous paper. 展开更多
关键词 CONSERVED DOMAIN DOMAIN SHUFFLING Deep EVOLUTION EVOLUTION Fold IMMUNOGLOBULIN Kinase Plant Immunity Resistance
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Distinct Processing of lncRNAs Contributes to Non-conserved Functions in Stem Cells 认领
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作者 CHEN Lingling 《中国科学院院刊:英文版》 2020年第2期116-117,共2页
Long noncoding RNAs(lncRNAs),which are longer than 200 nucleotides in length and lack protein coding potential,are pervasively transcribed in eukaryotic genomes.It is well established that lncRNAs play important roles... Long noncoding RNAs(lncRNAs),which are longer than 200 nucleotides in length and lack protein coding potential,are pervasively transcribed in eukaryotic genomes.It is well established that lncRNAs play important roles in gene expression in diverse cellular and biological progress. 展开更多
关键词 lncRNA CONSERVED diverse
Nonshifted Adiabatic Invariant on Time Scale 认领
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作者 SONG Chuanjing 《武汉大学自然科学学报:英文版》 CAS CSCD 2020年第4期301-306,共6页
Three aspects which include differential equation of motion, Noether symmetry and conserved quantity, perturbation to Noether symmetry and adiabatic invariant are investigated for the nonshifted Birkhoffian system, no... Three aspects which include differential equation of motion, Noether symmetry and conserved quantity, perturbation to Noether symmetry and adiabatic invariant are investigated for the nonshifted Birkhoffian system, nonshifted Hamiltonian system and nonshifted Lagrangian system, respectively. Then, some relationships among the three mechanic systems and some special cases of the main results are presented. Finally, an example is given to illustrate the application of the methods and results. 展开更多
关键词 time scale conserved quantity adiabatic invariant Birkhoffian system Hamiltonian system Lagrangian system
AN ABLOWITZ-LADIK INTEGRABLE LATTICE HIERARCHY WITH MULTIPLE POTENTIALS 认领
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作者 马文秀 《数学物理学报:B辑英文版》 SCIE CSCD 2020年第3期670-678,共9页
Within the zero curvature formulation,a hierarchy of integrable lattice equations is constructed from an arbitrary-order matrix discrete spectral problem of Ablowitz-Ladik type.The existence of infinitely many symmetr... Within the zero curvature formulation,a hierarchy of integrable lattice equations is constructed from an arbitrary-order matrix discrete spectral problem of Ablowitz-Ladik type.The existence of infinitely many symmetries and conserved functionals is a consequence of the Lax operator algebra and the trace identity.When the involved two potential vectors are scalar,all the resulting integrable lattice equations are reduced to the standard Ablowitz-Ladik hierarchy. 展开更多
关键词 Integrable lattice discrete spectral problem symmetry and conserved functional
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A VPE-like protease NtTPE8 exclusively expresses in the integumentary tapetum and is involved in seed development^FA 认领
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作者 Wei Wang Hanxian Xiong +3 位作者 Rongxin Lin Nantian Zhao Peng Zhao Meng-Xiang Sun 《植物学报:英文版》 SCIE CAS CSCD 2019年第5期598-610,共13页
Programmed cell death(PCD)is an essential process for development,and shows conserved cytological features in both plants and animals.Caspases are well-known critical components of the PCD machinery in animals.However... Programmed cell death(PCD)is an essential process for development,and shows conserved cytological features in both plants and animals.Caspases are well-known critical components of the PCD machinery in animals.However,currently few typical counterparts have been identified in plants and only several caspase-like proteases are known to be involved in plant PCD,indicating the existence of great challenge for confirming new caspase-like proteases and elucidating the mechanisms regulating plant PCD.Here,we report a novel cysteine protease,NtTPE8,which was extracted from tobacco seeds and confirmed as a new caspase-like protease.Recombinant NtTPE8 exhibited legumain and caspase-like proteolytic activities,both of which could be inhibited by the pan-caspase inhibitor(Z-VAD-FMK).Notably,NtTPE8 possessed several caspase activities and the capacity to cleave the cathepsin H substrate FVR,indicating a unique character of NtTPE8.NtTPE8 was exclusively expressed in the integumentary tapetum and thus,is the first specific molecular marker reported to date for this cell type.Downregulation of NtTPE8 caused seed abortion,via disturbing early embryogenesis,indicating its critical role in embryogenesis and seed development.In conclusion,we identified a novel caspase-like cysteine protease,NtTPE8,exclusively expressed in the integumentary tapetum that is involved in seed development. 展开更多
关键词 Programmed cell DEATH shows CONSERVED cytological exclusively EXPRESSED
Improving Cross-Protection against Influenza Virus Using Recombinant Vaccinia Vaccine Expressing NP and M2 Ectodomain Tandem Repeats 认领
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作者 Wenling Wang Baoying Huang +2 位作者 Xiuping Wang Wenjie Tan Li Ruan 《中国病毒学:英文版》 SCIE CAS CSCD 2019年第5期583-591,共9页
Conventional influenza vaccines need to be designed and manufactured yearly. However, they occasionally provide poor protection owing to antigenic mismatch. Hence, there is an urgent need to develop universal vaccines... Conventional influenza vaccines need to be designed and manufactured yearly. However, they occasionally provide poor protection owing to antigenic mismatch. Hence, there is an urgent need to develop universal vaccines against influenza virus. Using nucleoprotein(NP) and extracellular domain of matrix protein 2(M2e) genes from the influenza A virus A/Beijing/30/95(H3N2), we constructed four recombinant vaccinia virus-based influenza vaccines carrying NP fused with one or four copies of M2e genes in different orders. The recombinant vaccinia viruses were used to immunize BALB/C mice. Humoral and cellular responses were measured, and then the immunized mice were challenged with the influenza A virus A/Puerto Rico/8/34(PR8). NP-specific humoral response was elicited in mice immunized with recombinant vaccinia viruses carrying full-length NP, while robust M2e-specific humoral response was elicited only in the mice immunized with recombinant vaccinia viruses carrying multiple copies of M2e. All recombinant viruses elicited NP-and M2e-specific cellular immune responses in mice. Only immunization with RVJ-4M2eNP induced remarkably higher levels of IL-2 and IL-10 cytokines specific to M2e. Furthermore, RVJ-4M2eNP immunization provided the highest cross-protection in mice challenged with 20 MLD50 of PR8. Therefore, the cross-protection potentially correlates with both NP and M2e-specific humoral and cellular immune responses induced by RVJ-4M2eNP, which expresses a fusion antigen of full-length NP preceded by four M2e repeats. These results suggest that the rational fusion of NP and multiple M2e antigens is critical toward inducing protective immune responses, and the 4M2eNP fusion antigen may be employed to develop a universal influenza vaccine. 展开更多
关键词 Influenza A virus(IAV) CROSS-PROTECTION RECOMBINANT VACCINIA VIRUS CONSERVED antigen
PARAREAL ALGORITHMS APPLIED TO STOCHASTIC DIFFERENTIAL EQUATIONS WITH CONSERVED QUANTITIES 认领
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作者 Liying Zhang Weien Zhou Lihai Ji 《计算数学:英文版》 SCIE CSCD 2019年第1期48-60,共13页
In this paper,we couple the parareal algorithm with projection methods of the trajectory on a specifc manifold,defined by the preservation of some conserved quantities of stochastic differential equations.First,projec... In this paper,we couple the parareal algorithm with projection methods of the trajectory on a specifc manifold,defined by the preservation of some conserved quantities of stochastic differential equations.First,projection methods are introduced as the coarse and fine propagators.Second,we apply the projection methods for systems with conserved quantities in the correction step of original parareal algorithm.Finally,three mumerical experiments are performed by different kinds of algorithms to show the property of convergence in iteration,and preservation in conserved quantities of model systems. 展开更多
关键词 STOCHASTIC DIFFERENTIAL equation Parareal algorithm CONSERVED quantity Structurepreserving method
Noether Theorem on Time Scales for Lagrangian Systems in Event Space 认领
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作者 SHI Yufei ZHANG Yi 《武汉大学学报:自然科学英文版》 CAS CSCD 2019年第4期295-304,共10页
The Noether symmetry and the conserved quantity on time scales in event space are studied in this paper. Firstly, the Lagrangian of parameter forms on time scales in event space are established. The Euler-Lagrange equ... The Noether symmetry and the conserved quantity on time scales in event space are studied in this paper. Firstly, the Lagrangian of parameter forms on time scales in event space are established. The Euler-Lagrange equations and the second EulerLagrange equations of variational calculus on time scales in event space are established. Secondly, based upon the invariance of the Hamilton action on time scales in event space under the infinitesimal transformations of a group, the Noether symmetry and the conserved quantity on time scales in event space are established.Finally, an example is given to illustrate the method and results. 展开更多
关键词 time scales EVENT SPACE LAGRANGIAN system SYMMETRY CONSERVED quantity
Protein S-Nitrosylation in plants:Current progresses and challenges 认领
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作者 Jian Feng Lichao Chen Jianru Zuo 《植物学报:英文版》 SCIE CAS CSCD 2019年第12期1206-1223,共18页
Nitric oxide(NO)is an important signaling molecule regulating diverse biological processes in all living organisms.A major physiological function of NO is executed via protein S-nitrosylation,a redox-based the past de... Nitric oxide(NO)is an important signaling molecule regulating diverse biological processes in all living organisms.A major physiological function of NO is executed via protein S-nitrosylation,a redox-based the past decade,significant progress has been made in functional characterization of S-nitrosylated proteins Inviteposttranslational modification by covalently adding a NO molecule to a reactive cysteine thiol of a target protein.S-nitrosylation is an evolutionarily conserved mechanism modulating multiple aspects of cellular signaling.Duringin plants.Emerging evidence indicates that protein Snitrosylation is ubiquitously involved in the regulation of plant development and stress responses.Here we review current understanding on the regulatory mechanisms of protein S-nitrosylation in various biological processes in plants and highlight key challenges in this field. 展开更多
关键词 field. adding CONSERVED
Dissecting conserved cis-regulatory modules of Glu-1 promoters which confer the highly active endosperm-specific expression via stable wheat transformation 认领
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作者 Jihu Li Ke Wang +7 位作者 Genying Li Yulian Li Yong Zhang Zhiyong Liu Xingguo Ye Xianchun Xia Zhonghu He Shuanghe Cao 《作物学报:英文版》 SCIE CAS CSCD 2019年第1期8-18,共11页
Wheat high-molecular-weight glutenin subunits(HMW-GS)determine dough elasticity and play an essential role in processing quality.HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level,impl... Wheat high-molecular-weight glutenin subunits(HMW-GS)determine dough elasticity and play an essential role in processing quality.HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level,implemented through the interactions between cis-acting elements and trans-acting factors.However,transcriptional mechanismof Glu-1 genes remains elusive.Here we made a comprehensive analysis of cis-regulatory elements within 1-kb upstream of the Glu-1 start codon(-1000 to-1)and identified 30 conserved motifs.Based on motif distribution pattern,three conserved cis-regulatory modules(CCRMs),CCRM1(-300 to-101),CCRM2(-650 to-400),and CCRM3(-950 to-750),were defined,and their functions were characterized in wheat stable transgenic lines transformed with progressive 5′deletion promoter::GUS fusion constructs.GUS staining,qPCR and enzyme activity assays indicated that CCRM2 and CCRM3 could enhance the expression level of Glu-1,whereas the 300-bp promoter(-300 to-1),spanning CCRM1 and core region(-100 to-1),was enough to ensure accurate Glu-1 initiation at 7 days after flowering(DAF)and shape its spatiotemporal expression pattern during seed development.Further transgenic assays demonstrated that CCRM1-2(-300 to-209)containing CompleteHMWEnhancer(-246 to-209)was important for expression level but had no effect on expression specificity in the endosperm.In contrast,CCRM1-1(-208 to-101)was critical for both expression specificity and level of Glu-1.Our findings not only provide new insights to uncover Glu-1 transcription regulatory machinery but also lay foundations for modifying Glu-1 expression. 展开更多
关键词 CONSERVED cis-regulatory modules GLU-1 TRANSCRIPTIONAL regulation Transgenic wheat Triticum AESTIVUM
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Conserved sequences identify the closest living relatives of primates 认领
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作者 Mei-Ling Zhang Ming-Li Li +3 位作者 Adeola Oluwakemi Ayoola Robert W. Murphy Dong-Dong Wu Yong Shao 《动物学研究》 SCIE CAS CSCD 2019年第6期532-540,共9页
Elucidating the closest living relatives of extant primates is essential for fully understanding important biological processes related to the genomic and phenotypic evolution of primates, especially of humans. Howeve... Elucidating the closest living relatives of extant primates is essential for fully understanding important biological processes related to the genomic and phenotypic evolution of primates, especially of humans. However, the phylogenetic placement of these primate relatives remains controversial, with three primary hypotheses currently espoused based on morphological and molecular evidence. In the present study, we used two algorithms to analyze differently partitioned genomic datasets consisting of 45.4 Mb of conserved non-coding elements and 393 kb of concatenated coding sequences to test these hypotheses. We assessed different genomic histories and compared with other molecular studies found solid support for colugos being the closest living relatives of primates. Our phylogeny showed Cercopithecinae to have low levels of nucleotide divergence, especially for Papionini, and gibbons to have a high rate of divergence. The MCMCtree comprehensively updated divergence dates of early evolution of Primatomorpha and Primates. 展开更多
关键词 PHYLOGENY Colugos PRIMATES CONSERVED NON-CODING elements DIVERGENCE time
Framing Noether’s Theorem 认领
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作者 Caesar P. Viazminsky 《应用数学(英文)》 2018年第3期274-286,共13页
We discuss Noether’s theorem from a new perspective and show that the spatial continuous symmetries of a system are on one hand symmetries of the space and on the other hand are dictated by the system’s potential en... We discuss Noether’s theorem from a new perspective and show that the spatial continuous symmetries of a system are on one hand symmetries of the space and on the other hand are dictated by the system’s potential energy. The Noether’s charges arising from an infinitesimal motion, or a Killing vector field, of the space, are conserved if the Lie derivative of the potential energy by this vector field vanishes. The possible spatial symmetries of a mechanical system are listed according to the potential energy of the external forces. 展开更多
关键词 Noether’s THEOREM Continuous SPATIAL SYMMETRIES CONSERVED MOMENTA
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Detection of hyper-conserved regions in hepatitis B virus X gene potentially useful for gene therapy 认领
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作者 Carolina González David Tabernero +12 位作者 Maria Francesca Cortese Josep Gregori Rosario Casillas Mar Riveiro-Barciela Cristina Godoy Sara Sopena Ariadna Rando Marcal Yll Rosa Lopez-Martinez Josep Quer Rafael Esteban Maria Buti Francisco Rodríguez-Frías 《世界胃肠病学杂志:英文版》 SCIE CAS 2018年第19期2095-2107,共13页
AIM To detect hyper-conserved regions in the hepatitis B virus(HBV)X gene(HBX)5’region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various cl... AIM To detect hyper-conserved regions in the hepatitis B virus(HBV)X gene(HBX)5’region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various clinical stages(from chronic infection to cirrhosis and hepatocellular carcinoma,both HBeAg-negative and HBeAg-positive),and infected with HBV genotypes A-F and H.In a serum sample from each patient with viremia>3.5 log IU/mL,the HBX 5’end region[nucleotide(nt)1255-1611]was PCRamplified and submitted to next-generation sequencing(NGS).We assessed genotype variants by phylogenetic analysis,and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences(haplotypes)obtained by NGS.Conservation at the HBx protein amino acid(aa)level was also analyzed.RESULTS NGS yielded 1333069 sequences from the 27 samples,with a median of 4578 sequences/sample(2487-9279,IQR 2817).In 14/27 patients(51.8%),phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants.Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions,one in the HBX upstream non-coding region(nt 1255-1286)and the other in the 5’end coding region(nt 1519-1603).This last region coded for a conserved amino acid region(aa 63-76)that partially overlaps a Kunitz-like domain.CONCLUSION Two hyper-conserved regions detected in the HBX 5’end may be of value for targeted gene therapy,regardless of the patients’clinical stage or HBV genotype. 展开更多
关键词 HEPATITIS B virus HEPATITIS B X GENE HEPATITIS B X protein GENE therapy Next-generation sequencing HBV CONSERVED regions Small interference RNA
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Interaction between Bms1 and Rcll, two ribosome biogenesis factors, is evolutionally conserved in zebrafish and human 认领
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作者 Yong Wang Qinfang Zhu +4 位作者 Ling Huang Yanqing Zhu Jun Chen Jinrong Peng Li Jan Lo 《遗传学报:英文版》 SCIE CAS CSCD 2016年第7期467-469,共3页
<正>Ribosomes are large RNA and protein complexes that function as the machinery for translation protein synthesis(Boisvert et al.,2007;Ben-Shem et al.,2011;Henras et al.,2015;Khatter et al.,2015;McCann et al.,2... <正>Ribosomes are large RNA and protein complexes that function as the machinery for translation protein synthesis(Boisvert et al.,2007;Ben-Shem et al.,2011;Henras et al.,2015;Khatter et al.,2015;McCann et al.,2015).The eukaryotic ribosome is composed of two subunits,the 60S large subunit(LSU)and the 40S small subunit(SSU),which collectively comprise of four different ribosomal RNA(rRNA)species and more than 70 proteins(Ben-Shem et al.,2011;Henras et al.,2015;Khatter et al.,2015).The LSU contains 展开更多
关键词 RIBOSOME CONSERVED EUKARYOTIC subunit RIBOSOMAL RNA yeast comprise GTPASE VERTEBRATE
New Insights on Energy Conserved Planar Motion 认领
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作者 Maruthi R.Akella Sofokli Cakalli 《工程与科学中的计算机建模(英文)》 2016年第2期119-127,共9页
The planar motion of a particle within an arbitrary potential field is considered.The particle is additionally subject to an external force wherein the applied thrust-acceleration is constrained to remain normal to th... The planar motion of a particle within an arbitrary potential field is considered.The particle is additionally subject to an external force wherein the applied thrust-acceleration is constrained to remain normal to the velocity vector.The system is thus non-conservative but since the thrust force is non-working,the total energy is a conserved quantity.Under this setting,a major result of fundamental importance is established in this paper:that the flight direction angle(more precisely,the sine of the angle between the position and velocity vectors)is shown to always satisfy a linear first-order differential equation with variable coefficients that depend upon the underlying potential function.As a consequence,an analytical solution for the flight direction angle can be obtained directly in terms of the particle’s distance from the center of the field for a significant number of special cases for the potential function.In the case of J2 perturbed spacecraft motion within equatorial orbits,the problem is reduced to that of solving an incomplete elliptic integral.Another important implication of the main result established here is that motion problems subject to velocity-normal thrusting can always be reduced to the study of equivalent single degree-of-freedom conservative systems with an effective potential function.The paper concludes with various examples of both academic and practical interest including the study of bounded two-body Keplerian orbits and hodograph interpretetions. 展开更多
关键词 ENERGY CONSERVED SPACECRAFT motion FLIGHT direction angle velocitynormal THRUSTING effective potential hodograph interpretation
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Conserved termini and adjacent variable region of Twortlikevirus Staphylococcus phages 认领
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作者 XianglilanZhang HuaixingKang +13 位作者 YuyuanLi XiaodongLiu YuYang ShashaLi GuangqianPei QiangSun PengShu ZhiqiangMi YongHuang ZhiyiZhang YannanLiu XiaopingAn XiaoluXu YigangTong 《中国病毒学:英文版》 CAS CSCD 2015年第6期433-440,共8页
Methicillin-resistant Staphylococcus aureus(MRSA) is an increasing cause of serious infection,both in the community and hospital settings. Despite sophisticated strategies and efforts, the antibiotic options for treat... Methicillin-resistant Staphylococcus aureus(MRSA) is an increasing cause of serious infection,both in the community and hospital settings. Despite sophisticated strategies and efforts, the antibiotic options for treating MRSA infection are narrowing because of the limited number of newly developed antimicrobials. Here, four newly-isolated MRSA-virulent phages, IME-SA1, IMESA2, IME-SA118 and IME-SA119, were sequenced and analyzed. Their genome termini were identified using our previously proposed 'termini analysis theory'. We provide evidence that remarkable conserved terminus sequences are found in IME-SA1/2/118/119, and, moreover, are widespread throughout Twortlikevirus Staphylococcus phage G1 and K species. Results also suggested that each phage of the two species has conserved 5′ terminus while the 3′ terminus is variable. More importantly, a variable region with a specific pattern was found to be present near the conserved terminus of Twortlikevirus S. phage G1 species. The clone with the longest variable region had variable terminus lengths in successive generations, while the clones with the shortest variable region and with the average length variable region maintained the same terminal length as themselves during successive generations. IME-SA1 bacterial infection experiments showed that the variation is not derived from adaptation of the phage to different host strains. This is the first study of the conserved terminus and variable region of Twortlikevirus S. phages. 展开更多
关键词 Twortlikevirus STAPHYLOCOCCUS PHAGE CONSERVED termini VARIABLE region
Perturbation to Mei Symmetry and Adiabatic Invariants for Disturbed El-Nabulsi’s Fractional Birkhoff System 认领
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作者 宋传静 张毅 《理论物理通讯:英文版》 SCIE CAS CSCD 2015年第8期171-176,共6页
For El-Nabulsi’s fractional Birkhoff system, Mei symmetry perturbation, the corresponding Mei-type adiabatic invariants and Noether-type adiabatic invariants are investigated in this paper. Firstly, based on El-Nabul... For El-Nabulsi’s fractional Birkhoff system, Mei symmetry perturbation, the corresponding Mei-type adiabatic invariants and Noether-type adiabatic invariants are investigated in this paper. Firstly, based on El-NabulsiBirkhoff fractional equations, Mei symmetry and the corresponding Mei conserved quantity, Noether conserved quantity deduced indirectly by Mei symmetry are studied. Secondly, Mei-type exact invariants and Noether-type exact invariants are given on the basis of the definition of adiabatic invatiant. Thirdly, Mei symmetry perturbation, Mei-type adiabatic invariants and Noether-type adiabatic invariants for the disturbed El-Nabulsi’s fractional Birkhoff system are studied.Finally, two examples, Hojman-Urrutia problem for Mei-type adiabatic invariants and another for the Noether-type adiabatic invariants, are given to illustrate the application of the results. 展开更多
关键词 MEI SYMMETRY CONSERVED quantity ADIABATIC invarian
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