The transformer-2(tra-2) gene plays a key role in the regulatory hierarchy of sexual differentiation in somatic tissues and in the germline of Drosophila melanogaster.In this study,sequences and expression profiles of...The transformer-2(tra-2) gene plays a key role in the regulatory hierarchy of sexual differentiation in somatic tissues and in the germline of Drosophila melanogaster.In this study,sequences and expression profiles of tra-2 in the Chinese mitten crab Eriocheir sinensis were characterized.Four tra-2 isoforms,designated as Estra-2a,Estra-2b,Estra-2c,and Estra-2d,were isolated.They all contained an RNA-recognition motif(RRM) and a linker region,which shared high similarity with other reported tra-2s.Sequence analysis revealed that Estra-2a,Estra-2b and Estra-2c are encoded by the same genomic locus and are generated by alternative splicing of the pre-mRNA.Compared with the other three isoforms,Estra-2d lacks the RS2 domain.Quantitative real-time PCR showed that all four isoforms were highly expressed in the fertilized egg,and in the 2-4 cell and blastula stages compared with larval stages(P<0.01),suggesting their maternal origin in early embryonic developmental stages.Notably,Estra-2a was highly expressed in male somatic tissues,while Estra-2c was significantly highly expressed in the ovary.These results suggest that Estra-2c is involved in sexual differentiation of the Chinese mitten crab.Our findings provide basic information for further functional studies of the tra-2 gene/protein in this species.展开更多
In this paper,the different influences of lanthanum (La) and cerium (Ce) species on the stability of Y zeolite were studied by X-ray diffractometry (XRD),X-ray photoelectron spectroscopy (XPS),and multinuclear (27Al,2...In this paper,the different influences of lanthanum (La) and cerium (Ce) species on the stability of Y zeolite were studied by X-ray diffractometry (XRD),X-ray photoelectron spectroscopy (XPS),and multinuclear (27Al,29Si) solidstate nuclear magnetic resonance spectroscopy (NMR).It was found that the stability of Y zeolite could be enhanced by the introduction of La or Ce species;however,the former effect was more remarkable than the latter.These results were also confirmed theoretically by density functional calculations.There was a strong interaction between the rare earth (La or Ce) species and Y zeolite clusters,which restrained the formation of extra-framework aluminum and enhanced evidently the stability of Y zeolite.Furthermore,the interaction between La species and Y zeolite was stronger than that of Ce species with Y zeolite.展开更多
The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center....The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center. The photo-detached electron flux is evaluated on a screen placed at a large distance from the negative molecular ion. The electron flux on the screen displays strong interferences, the peak positions are related to the distance between the two centers in the negative molecular ion. We a/so obtained a simple analytical formula for the total photodetachment cross section. It approaches one and two times of the cross section for the one-center system in the high and lowphoton energy limits respectively.展开更多
By simplifying saturatedly magnetized wire-rope to magnetic dipoles of the same magnetic field strength, an equivalent magnetic dipoles model is developed and the measuring principle for recognising damage of broken w...By simplifying saturatedly magnetized wire-rope to magnetic dipoles of the same magnetic field strength, an equivalent magnetic dipoles model is developed and the measuring principle for recognising damage of broken wire was presented. The relevant calculation formulas were also deduced. A composite solution method about nonlinear optimization was given. An example was given to illustrate the use of the equivalent magnetic dipoles method for quantitative damage recognition, and demonstrates that the result of this method is consistent with the real situation, so the method is valid and practical. wire-rope, damage of broken wires, quantitative recognition, equivalent magnetic dipoles, simulate展开更多
The antigenic determinants of trichosanthin were predicted by molecular modeling. First, the threedimensional structure model of the antigen-binding fragment of anti-trichosanthin immunoglobulin E was built on the bas...The antigenic determinants of trichosanthin were predicted by molecular modeling. First, the threedimensional structure model of the antigen-binding fragment of anti-trichosanthin immunoglobulin E was built on the basis of its amino-acid sequence and the known three-dimensional structure of an antibody with similar sequence. Secondly, the preferable antigen-antibody interactions were obtained based on the known three-dimensional structure of trichosanthin and of the hypervariable regions of anti-trichosanthin immunoglobulin E. Two regions in the molecular surface of trichosanthin were found to form extensive interactions with the hypervariable regions of the antibody and have been predicted to be the possible antigenic determinants: one is composed of two polypeptide segments, Ile201-Glu210 and Ile225-Asp229, which are close to each other in the three-dimensional structure; and the other is the segment Lys173-Thr178. The former region seems to be the more reasonable antigenic determinant than the latter one.展开更多
Two hierarchies of nonlinear integrable positive and negative lattice equations are derived from a discrete spectrak problem. The two lattice hierarchies are proved to have discrete zero curvature representations asso...Two hierarchies of nonlinear integrable positive and negative lattice equations are derived from a discrete spectrak problem. The two lattice hierarchies are proved to have discrete zero curvature representations associated with a discrete spectral problem, which also shows that the positive and negative hierarchies correspond to positive and negative power expansions of Lax operators with respect to the spectral parameter, respectively. Moreover, the integrable lattice models in the positive hierarchy are of polynomial type, and the integrable lattice models in the negative hierarchy are of rational type. Further, we construct infinite conservation laws about the positive hierarchy.展开更多
目的描述四川省2007～2008年急性弛缓性麻痹(Acute Flaccid Paralysis,AFP)病例监测中,分离到的部分非脊髓灰质炎肠道病毒(Nonpolio Enterovirus,NPEV)的型别特征,探讨AFP病例可能的病原谱。方法对四川省2007～2008年AFP病例中分离到的1...目的描述四川省2007～2008年急性弛缓性麻痹(Acute Flaccid Paralysis,AFP)病例监测中,分离到的部分非脊髓灰质炎肠道病毒(Nonpolio Enterovirus,NPEV)的型别特征,探讨AFP病例可能的病原谱。方法对四川省2007～2008年AFP病例中分离到的14株NPEV进行基因测序定型。结果测序结果经比较分析,确定肠道病毒(Enterovirus,EV)A组的柯萨奇病毒A组4、5、10型(Coxsackievirus Group A Type4、5、10,CVA4、CVA5、CVA10)和EV71型(Type71,EV71)各1株;EVB组的埃柯病毒(Enteric Cytopathogenic Human Orphan Virus,ECHO;引起细胞病变的人肠道孤儿病毒)6型(ECHO6)和30型(ECHO30)各3株,ECHO251株,CVA91株,CVB3和CVB5各1株。结论四川省2007～2008年AFP病例的病原谱可能包括多型别的NPEV。展开更多
The authors prove the Hardy-Littlewood-Sobolev theorems for generalized fractional integrals L?α/2 for 0 < α < n/m, where L is a complex elliptic operator of arbitrary order 2m on Rn.
Let D be an integral domain, ＊a star-operation on D, and S a multiplicative subset of D. We define D to be an S-＊w-principal ideal domain if for each nonzero ideal I of D, there exist an element s ∈ S and a princip...Let D be an integral domain, ＊a star-operation on D, and S a multiplicative subset of D. We define D to be an S-＊w-principal ideal domain if for each nonzero ideal I of D, there exist an element s ∈ S and a principal ideal （c） of D such that sI （c） In this paper, we study some properties of S-＊w-principal ideal domains. Among other things, we study the local property, the Nagata type theorem, and the Cohen type theorem for S-＊w-principal ideal domains.展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A409)the Scientific and Technological Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘The transformer-2(tra-2) gene plays a key role in the regulatory hierarchy of sexual differentiation in somatic tissues and in the germline of Drosophila melanogaster.In this study,sequences and expression profiles of tra-2 in the Chinese mitten crab Eriocheir sinensis were characterized.Four tra-2 isoforms,designated as Estra-2a,Estra-2b,Estra-2c,and Estra-2d,were isolated.They all contained an RNA-recognition motif(RRM) and a linker region,which shared high similarity with other reported tra-2s.Sequence analysis revealed that Estra-2a,Estra-2b and Estra-2c are encoded by the same genomic locus and are generated by alternative splicing of the pre-mRNA.Compared with the other three isoforms,Estra-2d lacks the RS2 domain.Quantitative real-time PCR showed that all four isoforms were highly expressed in the fertilized egg,and in the 2-4 cell and blastula stages compared with larval stages(P<0.01),suggesting their maternal origin in early embryonic developmental stages.Notably,Estra-2a was highly expressed in male somatic tissues,while Estra-2c was significantly highly expressed in the ovary.These results suggest that Estra-2c is involved in sexual differentiation of the Chinese mitten crab.Our findings provide basic information for further functional studies of the tra-2 gene/protein in this species.
基金the Ministry of Science and Technology of China for providing financial support through the National 973 Project (Grant No. 2006CB202501)
文摘In this paper,the different influences of lanthanum (La) and cerium (Ce) species on the stability of Y zeolite were studied by X-ray diffractometry (XRD),X-ray photoelectron spectroscopy (XPS),and multinuclear (27Al,29Si) solidstate nuclear magnetic resonance spectroscopy (NMR).It was found that the stability of Y zeolite could be enhanced by the introduction of La or Ce species;however,the former effect was more remarkable than the latter.These results were also confirmed theoretically by density functional calculations.There was a strong interaction between the rare earth (La or Ce) species and Y zeolite clusters,which restrained the formation of extra-framework aluminum and enhanced evidently the stability of Y zeolite.Furthermore,the interaction between La species and Y zeolite was stronger than that of Ce species with Y zeolite.
基金The project supported by National Natural Science Foundation of China under Grant No. 90403028
文摘The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center. The photo-detached electron flux is evaluated on a screen placed at a large distance from the negative molecular ion. The electron flux on the screen displays strong interferences, the peak positions are related to the distance between the two centers in the negative molecular ion. We a/so obtained a simple analytical formula for the total photodetachment cross section. It approaches one and two times of the cross section for the one-center system in the high and lowphoton energy limits respectively.
基金Supported by the National Natural Science Foundation of China(50475166) and Natural Science Foundation of Shandong Province (Y2002F09) and Qingdao Scientific Bureau(04-3NS-10)
文摘By simplifying saturatedly magnetized wire-rope to magnetic dipoles of the same magnetic field strength, an equivalent magnetic dipoles model is developed and the measuring principle for recognising damage of broken wire was presented. The relevant calculation formulas were also deduced. A composite solution method about nonlinear optimization was given. An example was given to illustrate the use of the equivalent magnetic dipoles method for quantitative damage recognition, and demonstrates that the result of this method is consistent with the real situation, so the method is valid and practical. wire-rope, damage of broken wires, quantitative recognition, equivalent magnetic dipoles, simulate
文摘The antigenic determinants of trichosanthin were predicted by molecular modeling. First, the threedimensional structure model of the antigen-binding fragment of anti-trichosanthin immunoglobulin E was built on the basis of its amino-acid sequence and the known three-dimensional structure of an antibody with similar sequence. Secondly, the preferable antigen-antibody interactions were obtained based on the known three-dimensional structure of trichosanthin and of the hypervariable regions of anti-trichosanthin immunoglobulin E. Two regions in the molecular surface of trichosanthin were found to form extensive interactions with the hypervariable regions of the antibody and have been predicted to be the possible antigenic determinants: one is composed of two polypeptide segments, Ile201-Glu210 and Ile225-Asp229, which are close to each other in the three-dimensional structure; and the other is the segment Lys173-Thr178. The former region seems to be the more reasonable antigenic determinant than the latter one.
基金supported by the "Chunlei" Project of Shandong University of Science and Technology of China under Grant No. 2008BWZ070
文摘Two hierarchies of nonlinear integrable positive and negative lattice equations are derived from a discrete spectrak problem. The two lattice hierarchies are proved to have discrete zero curvature representations associated with a discrete spectral problem, which also shows that the positive and negative hierarchies correspond to positive and negative power expansions of Lax operators with respect to the spectral parameter, respectively. Moreover, the integrable lattice models in the positive hierarchy are of polynomial type, and the integrable lattice models in the negative hierarchy are of rational type. Further, we construct infinite conservation laws about the positive hierarchy.
文摘目的描述四川省2007～2008年急性弛缓性麻痹(Acute Flaccid Paralysis,AFP)病例监测中,分离到的部分非脊髓灰质炎肠道病毒(Nonpolio Enterovirus,NPEV)的型别特征,探讨AFP病例可能的病原谱。方法对四川省2007～2008年AFP病例中分离到的14株NPEV进行基因测序定型。结果测序结果经比较分析,确定肠道病毒(Enterovirus,EV)A组的柯萨奇病毒A组4、5、10型(Coxsackievirus Group A Type4、5、10,CVA4、CVA5、CVA10)和EV71型(Type71,EV71)各1株;EVB组的埃柯病毒(Enteric Cytopathogenic Human Orphan Virus,ECHO;引起细胞病变的人肠道孤儿病毒)6型(ECHO6)和30型(ECHO30)各3株,ECHO251株,CVA91株,CVB3和CVB5各1株。结论四川省2007～2008年AFP病例的病原谱可能包括多型别的NPEV。
基金Project supported by the National Natural Science Foundation of China (No.10171111, No.10371734)and the Foundation of Advanced Research Center, Zhongshan University.
文摘The authors prove the Hardy-Littlewood-Sobolev theorems for generalized fractional integrals L?α/2 for 0 < α < n/m, where L is a complex elliptic operator of arbitrary order 2m on Rn.
文摘Let D be an integral domain, ＊a star-operation on D, and S a multiplicative subset of D. We define D to be an S-＊w-principal ideal domain if for each nonzero ideal I of D, there exist an element s ∈ S and a principal ideal （c） of D such that sI （c） In this paper, we study some properties of S-＊w-principal ideal domains. Among other things, we study the local property, the Nagata type theorem, and the Cohen type theorem for S-＊w-principal ideal domains.
