【目的】对比分析猪繁殖与呼吸综合症病毒(PRRSV)阳性血清驯化和疫苗免疫两种方式对猪场后备母猪免疫抗体水平及繁殖性能的影响,为规模养殖场选择适宜免疫方式防控猪繁殖与呼吸综合症(PRRS)提供参考依据。【方法】以血清驯化和疫苗免疫...【目的】对比分析猪繁殖与呼吸综合症病毒(PRRSV)阳性血清驯化和疫苗免疫两种方式对猪场后备母猪免疫抗体水平及繁殖性能的影响,为规模养殖场选择适宜免疫方式防控猪繁殖与呼吸综合症(PRRS)提供参考依据。【方法】以血清驯化和疫苗免疫两种方式分别免疫90日龄后备母猪,1个月后经前腔静脉窦采血检测抗体水平,同时测定后备母猪第一胎的受胎率、分娩率、胎产仔数、胎产活仔数、产弱仔率、产死胎率、产畸形及木乃伊率等繁殖性能指标。【结果】血清驯化与疫苗免疫后备母猪的血清抗体阳性率分别为100.00%和99.30%,但疫苗免疫后备母猪的抗体水平离散度相对较低,且较集中。血清驯化与疫苗免疫后备母猪第一胎的受胎率(96.79%vs 97.11%)、分娩率(88.55%vs 88.96%)、胎产仔数(11.26 vs 11.41)、胎产活仔数(10.3 vs 10.5)、产弱仔率(3.61%vs 3.32%)、产死胎率(2.96%vs 2.99%)、产畸形及木乃伊率(4.35%vs 4.13%)相近,二者差异不显著(P>0.05),但均优于对照后备母猪。【结论】在确定养猪场内只流行一种血清型PRRSV时,可采用血清驯化替代疫苗免疫防控PRRS,除了能有效提高后备母猪的繁殖性能外,还具有成本低廉、操作简单的特点。展开更多
Increasing the detection efficiency （DE） is a hot issue in the development of the superconducting nanowire single photon detector （SNSPD）. In this work, a cavity-integrated structure coupled to the SNSPD is used t...Increasing the detection efficiency （DE） is a hot issue in the development of the superconducting nanowire single photon detector （SNSPD）. In this work, a cavity-integrated structure coupled to the SNSPD is used to enhance the light absorption of nanowire. Ultra-thin Nb films are successfully prepared by magnetron sputtering, which are used to fabricate Nb/Al SNSPD with the curve of lOOnm and the square area of 4 × 4μm2 by sputtering and the lift-off method. To characterize the optical and electrical performance of the cavity-integrated SNSPD, a reliable cryogenic research system is built up based on a He3 system. To satisfy the need of light coupling, a packaging structure with collimator is conducted. Both DE and the dark count rates increase with lb. It is also found that the DE of SNSPD with cavities can be up to 0.17% at the temperature of 0.7K under the infrared light of 1550nm, which is obviously higher than that of the SNSPD directly fabricated upon silicon without any cavity structure.展开更多
文摘【目的】对比分析猪繁殖与呼吸综合症病毒(PRRSV)阳性血清驯化和疫苗免疫两种方式对猪场后备母猪免疫抗体水平及繁殖性能的影响,为规模养殖场选择适宜免疫方式防控猪繁殖与呼吸综合症(PRRS)提供参考依据。【方法】以血清驯化和疫苗免疫两种方式分别免疫90日龄后备母猪,1个月后经前腔静脉窦采血检测抗体水平,同时测定后备母猪第一胎的受胎率、分娩率、胎产仔数、胎产活仔数、产弱仔率、产死胎率、产畸形及木乃伊率等繁殖性能指标。【结果】血清驯化与疫苗免疫后备母猪的血清抗体阳性率分别为100.00%和99.30%,但疫苗免疫后备母猪的抗体水平离散度相对较低,且较集中。血清驯化与疫苗免疫后备母猪第一胎的受胎率(96.79%vs 97.11%)、分娩率(88.55%vs 88.96%)、胎产仔数(11.26 vs 11.41)、胎产活仔数(10.3 vs 10.5)、产弱仔率(3.61%vs 3.32%)、产死胎率(2.96%vs 2.99%)、产畸形及木乃伊率(4.35%vs 4.13%)相近,二者差异不显著(P>0.05),但均优于对照后备母猪。【结论】在确定养猪场内只流行一种血清型PRRSV时,可采用血清驯化替代疫苗免疫防控PRRS,除了能有效提高后备母猪的繁殖性能外,还具有成本低廉、操作简单的特点。
基金Supported by the National Basic Research Program of China under Grant No 2011CBA00304the National Natural Science Foundation of China under Grant Nos 60836001 and 61174084the Tsinghua University Initiative Scientific Research Program under Grant No 20131089314
文摘Increasing the detection efficiency （DE） is a hot issue in the development of the superconducting nanowire single photon detector （SNSPD）. In this work, a cavity-integrated structure coupled to the SNSPD is used to enhance the light absorption of nanowire. Ultra-thin Nb films are successfully prepared by magnetron sputtering, which are used to fabricate Nb/Al SNSPD with the curve of lOOnm and the square area of 4 × 4μm2 by sputtering and the lift-off method. To characterize the optical and electrical performance of the cavity-integrated SNSPD, a reliable cryogenic research system is built up based on a He3 system. To satisfy the need of light coupling, a packaging structure with collimator is conducted. Both DE and the dark count rates increase with lb. It is also found that the DE of SNSPD with cavities can be up to 0.17% at the temperature of 0.7K under the infrared light of 1550nm, which is obviously higher than that of the SNSPD directly fabricated upon silicon without any cavity structure.
