| 1. | Separation on a new antigenic drift strain a3 of influenza viruses in guizhou
贵州省分离出一株甲3型流感病毒新变异株 |
| 2. | Antigenic drifts minor changes of influenza viruses lead to the emergence of new viral strains every year
每年，流感病毒会出现抗原漂移轻微改变，并产生新病毒品种。 |
| 3. | Seasonal outbreaks of ordinary influenza arise as a result of influenza viruses undergoing minor genetic changes known as antigenic drift
普通流感的季节性爆发，是由流感病毒出现称为抗原漂移的轻微基因变异所引起。 |
| 4. | Cause seasonal outbreaks of ordinary influenza arise as a result of influenza viruses undergoing minor genetic changes known as antigenic drift
普通流感的季节性爆发，是由流感病毒出现称为抗原漂移的轻微基因变异所引起。 |
| 5. | The surface antigens of influenza viruses undergo frequent changes . such changes can be minor called antigenic drift or major called antigenic shift
流感病毒的表面抗原会常常改变，这些改变有时较小，称为抗原漂移antigenic drift ，有时则较大，称为抗原转移antigenic shift 。 |
| 6. | To elucidate the antigenic drift and evolution of h9n2 subtype avian influenza viruses ( aivs ) , five isolates from the north of henan province during 1998 - 2002 were compared and analysed by cross - hemagglutinin inhibition test ( hi ) , cross - virus neutralization test ( vn ) in the chicken embryo and chicken embryo primary kidney cell ( cek ) and cross protection against challenge infection test
为了探讨h _ 9n _ 2亚型禽流感病毒的抗原性有否发生漂移，本研究从生物学角度和ha基因分子水平上对1998 ? 2002年间在河南省豫北地区分离到的5株h _ 9n _ 2亚型禽流感病毒的抗原性变化进行了比较和分析。 |
| 7. | The result shows that a vvibdv strain was obtained , the above work lay a important role for further studying on the molecular biological mechanism of antigenic drift and virulence variation of ibdv , molecular epedimiology , it also provided the basis for recombinant and gene deleted vaccine of ibdv
本实验可以帮助我们进一步探讨ibdv抗原性漂移和毒力变化的分子生物学机制，追溯ibdv的起源，理解病毒的传播方式。同时也为研制开发基因重组疫苗和缺失疫苗打下一定的基础。 |
| 8. | The results revealed that antigenic drift had occurred in virus strains of the same h9n2 subtype in the north of henan province during 1998 - 2002 . h9n2 subtype aivs were stable from 1998 to 1999 , since the mutual protection between 98a5 and 99s approached to 100 % , which was consistent with results in hi and vn tests
1998年和1999年h _ 9n _ 2亚型禽流感病毒较稳定， 98a5和99s毒株间的保护力接近100 ，在hi 、鸡胚中和、细胞中和试验结果的相关性均在0 . 74以上，表明两毒株间的抗原性相近。 |
