Comparative assessment of the state of urban soils based on their biological activity     

T. A. Trifonova  O. N. Sakhno  O. N. Zabelina  I. D. Feoktistova 《Moscow University Soil Science Bulletin》2014,69(3):112-115

The chemical properties and biological activity reflecting the nitrogen balance of soils have been studied to assess their ecological state in Vladimir. Changes in the biological activity of soils in urban areas have been revealed. They may be a theoretical basis for developing measures on protecting urban soils and rehabilitation of areas.  相似文献   

Cryopreservation and In Vitro culture of Preimplantation Embryos in Djungarian Hamster (Phodopus sungorus)          下载免费PDF全文

EYu Brusentsev  TO Abramova  IN Rozhkova  TN Igonina  VA Naprimerov  NYu Feoktistova  SYa Amstislavsky 《Reproduction in domestic animals》2015,50(4):677-683

Although embryo cryobanking was applied to Syrian golden and to Campbell's hamsters, no attempt has been made at freezing embryos in Djungarian hamsters. Four‐cell stage embryos were flushed from the reproductive ducts of pregnant females before noon of the third‐day post coitum and frozen in 0.25‐ml straws according to standard procedures of slow cooling. A mixture of permeating (ethylene glycol) and non‐permeating (sucrose) cryoprotectants was used. The thawing was performed by incubating at RT for 40 s followed by 40 s in a water bath at 30.0°C. Most (66.7%) of the non‐frozen four‐cell embryos developed up to the morula stage in rat one‐cell embryo culture medium (R1ECM). The use of hamster embryo culture medium (HECM) yielded fewer morulas (18.2%) during the same 24‐h period of culture. The rate of embryo's surviving the freezing–thawing procedures, as estimated by light microscopy, was 60.7–68.8%. After 24‐h culturing in R1ECM, 64.7% of frozen–thawed four‐cell embryos developed and all of them reached the morula stage. Supplementation of R1ECM with GM‐CSF (2 ng/ml) improved the rate of Djungarian hamster frozen–thawed embryo development: 100% of the four‐cell stage embryos developed, 50% of them achieved the morula stage, and 50% developed even further and reached the blastocyst stage within 24 h of culturing. This study reports the world's first successful transfer of frozen–thawed Djungarian hamster embryos yielding term pups. Taken together, the results of this study demonstrate the possibility of applying some key reproductive technologies, that is, embryo freezing/cryopreservation and in vitro culture, to Djungarian hamsters.  相似文献