Characteristics of the ionization tracks and interactions of uranium-238 nuclei in emulsion     

Heckman HH  Karant YJ  Friedlander EM 《Science (New York, N.Y.)》1982,217(4565):1137-1138

The acceleration and extraction of uranium-238 nuclei by the Bevalac have been confirmed by their visual detection in nuclear research emulsion. A preliminary result for the collision mean free path for stopping uranium-238 (energy 相似文献   

禽流感病毒抗原超滤浓缩重要参数的动态变化     

张彦杰  李爱芬 《中国兽药杂志》2007,41(10):16-17

采用世界先进的切向流超滤浓缩技术，对禽流感病毒（H9N2亚型）超滤浓缩成倍体积，测定血凝价HA和半数感染量EID50。结果HA成倍增加，废液HA呈阴性，病毒回收率达100％；受宿主鸡胚系统的影响，EID50与病毒量之间不是简单的直线关系，但病毒的活性不受影响。结果表明，所用超滤系统适用于禽流感病毒抗原的浓缩。  相似文献   

DNA疫苗佐剂研究进展     

项伟  赵玉军 《中国兽药杂志》2007,41(1):49-52

本文综述了具有载体功能佐剂:脂质体,免疫刺激复合物,减毒的侵袭性胞内细菌和免疫激活作用的佐剂:CpG寡核苷酸免疫调节序列,细胞因子,趋化因子,在DNA疫苗中应用的佐剂机理,相应的优缺点,佐剂应用及现状。  相似文献   

Improvement of the Culture Conditions for In Vitro Production of Cattle Embryos in a Portable CO₂ Incubator     

YJ Dong  MD Varisanga  NR Mtango  M Aono  T Otoi  & T Suzuki 《Reproduction in domestic animals》2001,36(6):313-318

The effects of different concentrations of growth hormone (GH) on in vitro maturation (IVM), fertilization (IVF) and culture (IVC) of bovine oocyte/embryos in CR1aa or CR2aa media using a simple CO₂ incubator were investigated. The IVM/IVF/IVC of oocytes were carried out in the presence of 0, 50, 100 and 200 ng/ml GH in the medium. The proportion of metaphase II oocytes was significantly higher (p < 0.05) in 200 ng/ml compared with 0 ng/ml GH in CR1aa medium (59 versus 85%, respectively), but this effect was not observed under CR2aa. Higher concentrations of GH yielded lower rates of unfertilized ova and thus superior cleavage rates (36.5 ± 0.2 and 63.5 ± 2.0% versus 17.5 ± 0.2 and 82.5 ± 1.5% or 40.4 ± 0.6 and 59.6 ± 1.4% versus 16.6 ± 1.2 and 83.4 ± 6.2% for 0 and 200 ng/ml GH in portable or ordinary incubator, respectively) in CR1aa. This dose‐dependent effect was also observed in the percentages of transferable embryos, although not statistically different (17.2 ± 1.7 versus 27.3 ± 1.8% and 16.6 ± 3.1 versus 26.0 ± 1.4%, for 0 versus 200 ng/ml GH in portable and ordinary incubator, respectively). In contrast to the CR1aa, different concentrations of GH in CR2aa medium did not increase either fertilization or cleavage rates. In fact, higher concentrations of GH in this medium negatively affected the rate of transferable embryos. Hence, percentages of transferable embryos obtained in the portable incubator under 0 or 50 ng/ml GH were higher (p < 0.05) compared with those obtained in 100 or 200 ng/ml GH (35.4 ± 5.7 or 40.5 ± 5.4% versus 22.4 ± 2.4 or 15.5 ± 2.1%, respectively). There was however, no significant difference in the rate of transferable embryos in an ordinary incubator employing CR2aa medium, but the trend was more or less similar to that observed in the portable incubator. Despite the fact that relatively fewer oocytes were employed for the culture in the ordinary incubator, overall results observed employing the simple portable CO₂ incubator were within the range of those obtained in an ordinary incubator; implying that the simple portable incubator can effectively be employed for the in vitro production of bovine embryos under field conditions.  相似文献   

Transcriptome analysis of the uniparous and multiparous goats ovaries          下载免费PDF全文

FY Guo  YJ Zhao  JH Zhang  ZQ Zhao 《Reproduction in domestic animals》2016,51(6):877-885

  相似文献   

An Inter‐Subspecies Cloned Buffalo (Bubalus bubalis) Obtained by Transferring of Cryopreserved Embryos via Somatic Cell Nuclear Transfer     

BZ Yang  CY Yang  RC Li  GS Qin  XF Zhang  CY Pang  MT Chen  FX Huang  Z Li  HY Zheng  YJ Huang  XW Liang 《Reproduction in domestic animals》2010,45(5):e21-e25

The aim of this study was to explore the feasibility of cryopreservation of inter‐subspecies cloned embryos in buffalo. In our experiment, river buffalo ear fibroblast nucleus was fused into swamp buffalo oocyte cytoplasm. The blastocyst formation rate for nuclear transfer of freshly thawed cells was not different from those of growing cells, confluent or serum‐starved cells. A total of 122 cloned blastocysts derived from cryopreserved fibroblasts were cryopreserved and thawed, 37 were survived, the cryosurvival rate was 30.3%. The survived blastocysts were transferred into 15 recipient buffalos. Five of the recipients established pregnancy, but four of them aborted on day 53, 59, 145 and 179 of gestation respectively. One cross‐bred buffalo (Murrah × Swamp buffalo (2n = 49) received three embryos delivered a 40.5 kg female calf by natural delivery on day 320 of gestation. Up to now (13‐month old), the cloned calf has been growing well with no abnormity observed. These results demonstrated that cryopreservation of inter‐subspecies cloned embryos is feasible to produce buffalo offspring.  相似文献