The developmental competence of porcine parthenotes cultured in porcine zygote medium-3 （PZM-3） and North Carolina State University-23 （NCSU-23） media was investigated. After in vitro maturation oocytes were elect...The developmental competence of porcine parthenotes cultured in porcine zygote medium-3 （PZM-3） and North Carolina State University-23 （NCSU-23） media was investigated. After in vitro maturation oocytes were electro-activated, and the subsequent developmental competence, rates of apoptotic, fragmented and arrested embryos from the two media were evaluated. Also, the ratio of mRNA expression of Bcl-2 and Bax gene was determined. Results demonstrated that cleavage, blastocyst, hatched blastocyst rates, and blastocyst cell numbers were significantly higher in PZM-3 than in NCSU-23. The rate of fragmented embryos in PZM-3 was lower than in NCSU-23 on d 1 and 3 （P〈0.05） while the percentage of arrested embryo was lower in PZM-3 than in NCSU-23 on d 4 and 5 （P〈0.05）. TUNEL positive signals were higher in NCSU-23 than in PZM-3 from d 3 to 7 （P〈0.05）. The ratios of Bcl-2 and Bax mRNA expression in embryos were higher on d 5 than on d 3 and 1 in PZM-3 （P〈0.05）. In contrast, the ratios of Bcl-2 and Bax mRNA expression in embryos on d 1 were higher than on d 3 and 5 in NCSU-23 （P〈0.05）. Additionally, the ratios of Bcl-2 and Bax mRNA expression in embryos in PZM-3 were higher than in NCSU-23 on d 3 and 5 （P〈0.05）. In conclusion, lower apoptotic embryo rates and down-regulating Bax together with up-regulating expression of Bcl-2 transcripts may be responsible for the better developmental competence of porcine parthenotes in PZM-3.展开更多
On June 25, 2016, the Long March 7(LM-7) launch vehicle completed its maiden flight successfully. LM-7, as a new generation of medium and basic launch vehicle based on the design concepts of non-toxic and nonpolluting...On June 25, 2016, the Long March 7(LM-7) launch vehicle completed its maiden flight successfully. LM-7, as a new generation of medium and basic launch vehicle based on the design concepts of non-toxic and nonpolluting, was developed for the purpose of launching a cargo spacecraft to the Chinese space station. Based on the experience on launching cargo spacecraft and satellites, LM-7 can be adapted for mainstream satellite launch missions in the future with its characteristics of serialization and continuous optimization. LM-7 is expected to be used to launch manned spacecraft in the future. This paper presents a general review of LM-7 with regard to the general scheme and provides references for the development prospects of a medium launch vehicle series in China.展开更多
基金funded by the National Natural Science Foundation of China (31072031)the Key Research Program of Ministry of Education of China(109018)
文摘The developmental competence of porcine parthenotes cultured in porcine zygote medium-3 （PZM-3） and North Carolina State University-23 （NCSU-23） media was investigated. After in vitro maturation oocytes were electro-activated, and the subsequent developmental competence, rates of apoptotic, fragmented and arrested embryos from the two media were evaluated. Also, the ratio of mRNA expression of Bcl-2 and Bax gene was determined. Results demonstrated that cleavage, blastocyst, hatched blastocyst rates, and blastocyst cell numbers were significantly higher in PZM-3 than in NCSU-23. The rate of fragmented embryos in PZM-3 was lower than in NCSU-23 on d 1 and 3 （P〈0.05） while the percentage of arrested embryo was lower in PZM-3 than in NCSU-23 on d 4 and 5 （P〈0.05）. TUNEL positive signals were higher in NCSU-23 than in PZM-3 from d 3 to 7 （P〈0.05）. The ratios of Bcl-2 and Bax mRNA expression in embryos were higher on d 5 than on d 3 and 1 in PZM-3 （P〈0.05）. In contrast, the ratios of Bcl-2 and Bax mRNA expression in embryos on d 1 were higher than on d 3 and 5 in NCSU-23 （P〈0.05）. Additionally, the ratios of Bcl-2 and Bax mRNA expression in embryos in PZM-3 were higher than in NCSU-23 on d 3 and 5 （P〈0.05）. In conclusion, lower apoptotic embryo rates and down-regulating Bax together with up-regulating expression of Bcl-2 transcripts may be responsible for the better developmental competence of porcine parthenotes in PZM-3.
文摘On June 25, 2016, the Long March 7(LM-7) launch vehicle completed its maiden flight successfully. LM-7, as a new generation of medium and basic launch vehicle based on the design concepts of non-toxic and nonpolluting, was developed for the purpose of launching a cargo spacecraft to the Chinese space station. Based on the experience on launching cargo spacecraft and satellites, LM-7 can be adapted for mainstream satellite launch missions in the future with its characteristics of serialization and continuous optimization. LM-7 is expected to be used to launch manned spacecraft in the future. This paper presents a general review of LM-7 with regard to the general scheme and provides references for the development prospects of a medium launch vehicle series in China.
