The rat chimera is an important animal model for the study of complex human diseases. In the present study we evaluated the chimeric potential of rat inner cell masses （ICMs） and fetal neural stem （FNS） cells. In ...The rat chimera is an important animal model for the study of complex human diseases. In the present study we evaluated the chimeric potential of rat inner cell masses （ICMs） and fetal neural stem （FNS） cells. In result, three rat chimeras were produced by day 5 （D5） Sprague-Dawley （SD） blastocysts injected with ICMs derived from day 6 （D6） and D5 Dark Agouti （DA） blastocysts; four rat chimeras had been generated by D5 DA blastocyst injected with D5 SD ICMs. For the requirement of gene modification, cultured rat inner cell mass cells were assessed to produce chimeras, but no chimeras were generated from injected embryos. The potential to generate chimeras from rFNS and transfected rFNS cells were tested, but no chimeric pups were produced. Only 2 of 41 fetuses derived from D5 DA blastocyst injection with SD LacZ transfected rFNS cells showed very low number of LacZ positive cells in the section. These results indicate that DA and SD rat ICMs arc able to contribute to chimeras, but their potential decreases significantly after culture in vitro （P〈0.05）, and rFNS cells only have the potential to contribute to early fetal development.展开更多
The soccer is an extremely universal movement that has received populace’s affection, natural, the soccer teaching also entered university’s classroom that becomes in the university physical education the important ...The soccer is an extremely universal movement that has received populace’s affection, natural, the soccer teaching also entered university’s classroom that becomes in the university physical education the important constituent. Speaking of the university students, the soccer is not merely the simple sports project which may help the student more importantly to build up strength the healthy body, enriches own after school life, therefore has received the general university student’s affection, moreover the soccer also has the unique charm, it has the oneself quite obvious characteristic in the sports, for instance its grouping development, location request and so on, these all deep attraction student vision, simultaneously also have been receiving the social people from all walks of life’s widespread attention. Nowadays, in the physical education curriculum of colleges and universities, the teaching of students’ football is mainly the knowledge and skill of soccer, ignoring the cooperation between the students. This traditional teaching mode cannot adapt to the teaching reform and quality education The implementation of physical education teachers in the teaching of football has been controversial and questioned, this is all the college physical education teachers face new challenges and new problems. This paper mainly analyzes and discusses the problems existing in college football teaching, aiming at these problems puts forward the corresponding reform measures and optimization strategy, and hope to provide certain reference for the development of football teaching in colleges and universities.展开更多
On August 2,a twin-segment solid rocket motor of the largest diameter,grain mass and thrust in China completed its ground test firing with success.The3 m solid motor was independently developed by the Academy of Aeros...On August 2,a twin-segment solid rocket motor of the largest diameter,grain mass and thrust in China completed its ground test firing with success.The3 m solid motor was independently developed by the Academy of Aerospace Solid Propulsion Technology（AASPT）under CASC.展开更多
文摘The rat chimera is an important animal model for the study of complex human diseases. In the present study we evaluated the chimeric potential of rat inner cell masses （ICMs） and fetal neural stem （FNS） cells. In result, three rat chimeras were produced by day 5 （D5） Sprague-Dawley （SD） blastocysts injected with ICMs derived from day 6 （D6） and D5 Dark Agouti （DA） blastocysts; four rat chimeras had been generated by D5 DA blastocyst injected with D5 SD ICMs. For the requirement of gene modification, cultured rat inner cell mass cells were assessed to produce chimeras, but no chimeras were generated from injected embryos. The potential to generate chimeras from rFNS and transfected rFNS cells were tested, but no chimeric pups were produced. Only 2 of 41 fetuses derived from D5 DA blastocyst injection with SD LacZ transfected rFNS cells showed very low number of LacZ positive cells in the section. These results indicate that DA and SD rat ICMs arc able to contribute to chimeras, but their potential decreases significantly after culture in vitro （P〈0.05）, and rFNS cells only have the potential to contribute to early fetal development.
文摘The soccer is an extremely universal movement that has received populace’s affection, natural, the soccer teaching also entered university’s classroom that becomes in the university physical education the important constituent. Speaking of the university students, the soccer is not merely the simple sports project which may help the student more importantly to build up strength the healthy body, enriches own after school life, therefore has received the general university student’s affection, moreover the soccer also has the unique charm, it has the oneself quite obvious characteristic in the sports, for instance its grouping development, location request and so on, these all deep attraction student vision, simultaneously also have been receiving the social people from all walks of life’s widespread attention. Nowadays, in the physical education curriculum of colleges and universities, the teaching of students’ football is mainly the knowledge and skill of soccer, ignoring the cooperation between the students. This traditional teaching mode cannot adapt to the teaching reform and quality education The implementation of physical education teachers in the teaching of football has been controversial and questioned, this is all the college physical education teachers face new challenges and new problems. This paper mainly analyzes and discusses the problems existing in college football teaching, aiming at these problems puts forward the corresponding reform measures and optimization strategy, and hope to provide certain reference for the development of football teaching in colleges and universities.
文摘On August 2,a twin-segment solid rocket motor of the largest diameter,grain mass and thrust in China completed its ground test firing with success.The3 m solid motor was independently developed by the Academy of Aerospace Solid Propulsion Technology（AASPT）under CASC.
