A cellulose xanthate supported palladium(0) complex was synthesized using a simple method and characterized by XPS, TG/DTA
etc. The complex has good thermal stability from room temperature to 250 °C and it was found to be an efficient catalyst for
the Heck reaction of acrylic acid or styrene with aryl iodide at low temperature under atmospheric pressure, and the substituted
trans-cinnamic acid or 1, 2-stilbene was obtained with high yield at 90 °C. The reaction duration is about 8 h. The cellulose xanthate
supported palladium(0) complex could be separated from the reaction mixture easily and reused for several cycles. The yield
of the product was up to 55.3% when the catalyst was run for 10 times. The active center in the complex is Pd metal.
The present study was designed to investigate the cryotolerance of
fertilised (IVF) mouse embryos at various preimplantation developmental stages. IVF mouse embryos were vitrified by the open-pulled straw (OPS) method. After warming, embryos were morphologically evaluated and assessed by their development to blastocysts, hatched blastocysts or term. The results showed that a high proportion (93.3–100.0%) of vitrified embryos at all developmental stages were morphologically normal after recovery. The developmental rate of vitrified 1-cell embryos to blastocyst (40.0%) or hatched blastocyst (32.7%) or term (9.3%) was significantly lower than that from other stages (P < 0.05). Vitrified embryos from 2-cell to early blastocyst stage showed similar blastocyst (71.8–89.5%) and hatched blastocyst rates (61.1–69.6%) and could develop to term without a significant loss of survival compared with those of fresh embryos (P > 0.05). Vitrified 2-cell embryos showed the highest survival rate
(50.6%, 88/174), compared with that from other stages (9.3–30.5%, P < 0.05). The data demonstrate that the OPS method is suitable for the cryopreservation of IVF mouse embryos from 2-cell stage to early blastocyst stage without a significant loss of survival. Embryos at the 2-cell stage had the best tolerance for cryopreservation in the present study.