Development of Annexin V Technology for Removal of Dead Spermatozoa from Bovine Spermatozoa and Its Application in Frozen Sexed Semen Production

[Objectives]This study was conducted to develop a molecular marker immunomagnetic bead sorting technology method that can specifically identify dead spermatozoa.[Methods]This study first confirmed the specific binding of Annexin V to dead bovine spermatozoa,and tried to remove dead spermatozoa in semen combining with the immunomagnetic bead technology,so as to improve the separation efficiency of target spermatozoa in the process of sex-controlled semen preparation on a flow cytometer.[Results]The spermatozoon motility,membrane integrity and mitochondrial activity after sorting and the rate of dead spermatozoa during the on-machine X/Y separation were all improved to different degrees(P<0.05),indicating that the technical process design could effectively remove some dead spermatozoa,and there was no significant effect on frozen sexed semen prepared from the separated X or Y spermatozoa(P>0.05),indicating that the technical process did not cause additional damage to the spermatozoa.[Conclusions]Combining the specificity of Annexin V with the immunomagnetic bead method could effectively remove dead spermatozoa from bovine spermatozoa,and significantly reduce the rate of dead spermatozoa in bovine permatozoa during sex-controlled separation(P<0.05).The method developed can effectively improve the production efficiency of frozen sexed semen of dairy cows,reduce the production cost,and promote the industrial application of the product.

Synergy of photocatalytic reduction and adsorption for boosting uranium removal with PMo_(12)/UiO-66 heterojunction

In this work,we proposed a new U(Ⅵ)removal strategy combining adsorption and photocatalytic reduction by the PMo_(12)/UiO-66 heterojunctions.The PMo_(12)has been encapsulated in the cavities of Ui O-66 by a one-step hydrothermal method,and the PMo_(12)/UiO-66 exhibited high adsorption capacity and photocatalytic activity.The maximal theoretical sorption capacity of U(Ⅵ)on 15%PMo_(12)/UiO-66 reached225.36 mg/g and the photoreduction rate of 15%PMo_(12)/UiO-66 is about thirty times as much as UiO-66.Under the light irradiation,the photogenerated electrons rapidly transport from UiO-66 to PMo_(12),and the photo-generated electrons could efficiently reduce the pre-enriched U(Ⅵ)to U(IV).This work provides new insights into remediation of the radioactive environment.