Objective:To develop a biotin-streptavidin system (BAS)-mediated folate receptor (FR)-targeted quantum dot (QD) fluorescent probe and preliminarily validate the targeting ability and signal amplification effect of the probe. Methods: Streptavidin (SA) was covalently coupled with QD through the active ester method;the physical characteristics of the prepared QD-SA were veri-fied. Biotinylated folate was synthesized through the carrier bovine serum albumin using the same method and then reacted with QD-SA to form the special probe. The probe was used to identify SKOV3 cells and FR-negative A549 cells to verify its targeting speci-ficity. QD-SA was used as the contrast. SKOV3 cells were imaged using the BAS-mediated FR-targeted QD probe with a biotinylated folate incubation time of 1 or 4 h. Various reaction times were also tested between the probe and the QD-FA that was formed without BAS mediation. Results:The BAS-mediated FR-targeted QD probe specifically recognized FR-positive SKOV3 cells. The probe ob-tained higher fluorescent intensity after 4 h than after 1 h of biotinylated folate incubation. The BAS-mediated FR-targeted QD probe al-so had a stronger fluorescent signal than the QD-FA probe. Conclusion:The proposed probe presents a great potential in the early diag-nosis of ovarian cancer because of its high specificity and sensitivity.

ObjectiveTo establish a set of single nucleotide polymorphisms (SNP) detection protocol for inbred rats based on multiplex PCR-ligase detection reaction (LDR). MethodsA total of 40 rats SNP sites were selected on chromosomes 1-20 and X of rats among 5 inbred strains of rats, and the 40 SNP sites were randomly divided into four groups. A genetic detection protocol for 4 groups of SNP in inbred rats based on multiplex PCR-LDR technology was constructed. 9 commonly used rat strains from two other domestic rat suppliers were detected by this protocol. Finally, the feasibility of this protocol was verified by comparing the amplification effects of different DNA polymerases by a third-party laboratory. ResultsWhen using the constructed SNP detection protocol for inbred rats to test 5 rat strains, all sites in each sample obtained good amplification results. The 9 commonly used rat strains from two other rat suppliers in china were also well amplified by this SNP detection protocol, and 40 SNPs were homozygous in each Inbred strain. The results of detection of the same rat DNA samples with three different DNA polymerases showed that the Multiplex PCR Kit, AmpliTaq Gold 360 DNA polymerase and Platinum II Taq hot start DNA polymerase had electrophoretic peaks of amplification products at all SNP sites in groups 1 to 3, and Platinum II Taq hot start DNA polymerase had one less electrophoretic peak of the amplification products at the SNP sites in group 4. In addition, inter-laboratory comparisons showed consistent results for the same amplification system. ConclusionBased on multiplex PCR-LDR technology, this study successfully established a SNP detection protocol for rats covering all autosomes and X chromosomes with the excellent stability and repeatability.

Objective To analyze the application value of uterine artery flow and cerebral placental rate(CPR)in diagnosing fetal growth restriction(FGR).Methods A total of 114 pregnant women with clinically diagnosed late-onset FGR who were hospitalized in Jiangxi Maternal and Child Health Hospital from January 2021 to June 2022 were assigned to study group,and 122 pregnant women with normal intrauterine development were assigned to control group.The blood flow parameters of uterine artery(UtA),umbilical artery(UA)and middle cerebral artery(MCA)in two groups were determined by ultrasound,and CPR in two groups was calculated.The blood flow difference and pregnancy outcome of two groups were compared.Receiver operating characteristic(ROC)curve was used to analyze the application value of UtA and CPR alone and combined in the clinical diagnosis of FGR.Results The UtA resistance index(RI)of pregnant women in study group was higher than that of control group,the fetal UA blood flow parameter was higher than that of control group,the MCA blood flow parameter and the CPR value were both lower than those of control group,the differences were statistically significant(P<0.05).The birth weight and 1min Apgar score of study group were lower than those of control group(P<0.001).In addition,the incidence of emergency cesarean section operation,premature delivery and neonates transferred to neonatal intensive care unit(NICU)due to various complications in study group were significantly higher than those in control group(P<0.05).ROC curve showed that in predicting FGR,the area under the curve(AUC)of UtA-RI was 0.82(95%CI:0.77-0.88).The predictive efficiency of CPR was 0.75(95%CI:0.69-0.81).The combination of UtA-RI and CPR parameters had the highest efficiency in predicting FGR,with an AUC of 0.92(95%CI:0.89-0.95).Conclusion CPR combined with UtA-RI monitoring has clinical application value for early detection of FGR,guiding intervention,and improving adverse perinatal outcomes.