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11.
Kanchana PUNYAWAI Nitira ANAKKUL Kanokwan SRIRATTANA Yoshio AIKAWA Siwat SANGSRITAVONG Takashi NAGAI Kei IMAI Rangsun PARNPAI 《The Journal of reproduction and development》2015,61(5):431-437
This study was designed to compare the efficiency of the Cryotop method and that of two methods that employ a micro volume air cooling (MVAC) device by analyzing the survival and development of bovine oocytes and blastocysts vitrified using each method. In experiment I, in vitro-matured (IVM) oocytes were vitrified using an MVAC device without direct contact with liquid nitrogen (LN2; MVAC group) or directly plunged into LN2 (MVAC in LN2 group). A third group of IVM oocytes was vitrified using a Cryotop device (Cryotop group). After warming, vitrified oocytes were fertilized in vitro. There were no significant differences in cleavage and blastocyst formation rates among the three vitrified groups, with the rates ranging from 53.1% to 56.6% and 20.0% to 25.5%, respectively; however, the rates were significantly lower (P < 0.05) than those of the fresh control group (89.3% and 43.3%, respectively) and the
solution control group (87.3% and 42.0%, respectively). In experiment II, in vitro-produced (IVP) expanded blastocysts were vitrified using the MVAC, MVAC in LN2 and Cryotop methods, warmed and cultured for survival analysis and then compared with the solution control group. The rate of development of vitrified-warmed expanded blastocysts to the hatched blastocyst stage after 24 h of culture was lower in the MVAC in LN2 group than in the solution control group; however, after 48–72 h of culture, the rates did not significantly differ between the groups. These results indicate that the MVAC method without direct LN2 contact is as effective as the standard Cryotop method for vitrification of bovine IVM oocytes and IVP expanded blastocysts. 相似文献
12.
Hai T. H. Nguyen Geoff Deverteuil Neil Wrigley Kanchana N. Ruwanpura 《Growth and change》2014,45(2):377-396
Academic interest on domestic regulatory (and re‐regulatory) impacts of retail foreign direct investment remains surprisingly under‐researched, despite high‐profile campaigns, particularly in Southeast Asia, to rein in the expansion of retail transnational corporations. This paper focuses on the trends of re‐regulation of foreign retailers, particularly in the food sector, in Vietnam before and after the accession to the World Trade Organization (WTO) in 2007. The findings reveal a complex layering of regulation, some of it a holdover from the pre‐2007 period and some of it occurring since WTO accession, in the form of the controversial Economic Needs Test. 相似文献