Objective To construct eukaryotic expression vector of small hairpin RNA vector targeting hepatitis B virus core protein in HepG2.2.15 cells,and to verify the interfering effect.Methods To design and synthesize small interfering RNA sequence against HBc gene (ayw subtype) which locates between 2147 bp to 2165 bp in the HBV genome.The siRNA fragment were inserted into pSilencer3.1-H1 neo vector.The recombinants were transformed into E.coli DHSα successfully.The recombinant plasmids were identified by Eco RI enzyme digestion and sequenced.Finally,The HepG2.2.15 cells were transfected with the vector by using lipofectamine method to identify its interfering effect.Results The eukaryotic expression vector containing small hairpin RNA targeting HBV core protein was constructed successfully and named as pshRNA-HBc.The recombinant plasmids were identified by SalI or EcoRI enzyme digestion and sequenced.The silencing effect was detected by using revere transcription polymerase chain reaction (RTPCR) and the secretion of HBsAg and HBeAg in the supernatant of HepG2.2.15 cells.The result showed that the interfering effect was specific and efficient.Conclusion The small interfering RNA targeting HBV core protein in HepG2.2.15 cells was constructed successfully,which may be useful for studying the biological functions of HBc in the future.

【Objective】 To evaluate the association between prophylactic plasma transfusion and postoperative bleeding rate in critically ill patients undergoing different invasive procedures. 【Methods】 The information of ICU patients who received different invasive procedures from January 2019 to December 2019 in 6 tertiary hospitals in China were retrospectively investigated. The inclusion criteria of patients were as follows: age ≥ 18 years; received invasive procedures; INR ≥ 1.5 within 72 hours before surgery. Exclusion criteria were patients with incomplete case records. The patients finally included in the study were divided into prophylactic plasma transfusion group and non-prophylactic plasma transfusion group according to their plasma transfusion status. The outcome variable was the incidence of invasive procedure-related bleeding within 48 hours after different invasive procedures. 【Results】 A total of 407 patients underwent invasive procedures, and 362 patients were finally included in this study after excluding 45 patients with incomplete case records. The proportions of prophylactic plasma transfusion in different types of invasive procedures were central venous catheterization (46/146, 31.5%), thoracentesis (13/37, 35.1%), bronchoscopy (8/31, 25.8%), tracheal intubation (9/38, 23.7%), arterial catheterization (9/50, 18.0%) and others (13/60, 21.7%). The bleeding rates showed that different invasive procedures presented no statistical difference between the groups received plasma transfusion or not. In the prophylactic plasma transfusion group, the bleeding rate of arterial catheterization (4/9, 44.4%) was the highest, but all were potential bleeding, followed by tracheal intubation (4/10, 40.0%) and central venous intubation (16/46, 34.8%), with a higher rate of significant bleeding. 【Conclusion】 Prophylactic infusion of plasma did not reduce the bleeding rate after different invasive procedures, but prospective studies are needed to further confirm the conclusion; this study also provides a certain data basis for later prospective studies.