OBJECTIVE To study the toxicity of zinc oxide nanoparticles (ZnO-NPs) on murine macrophage Ana-1 cells and the mechanism.METHODS Ana-1 cells were incubated with ZnO-NP (2.5-160 mg· L-1).Cell viability was investigated by MTT assay.The integrity of cell membrane was investigated by acridine orange-ethidium bromide (AO-EB) staining.The intracellular uptake of ZnO-NP and the percentage of sub-G1 of Ana-1 cells were detected by flow cytometry.Zinc ions were determined by fluorescent probe.The change of cell viability was studied after chelating zinc ions with ethylene diamine tetraacetic acid (EDTA).RESULTS ZnO-NP 2.5,5,10 and 20 mg· L-1 decreased cell viability of Ana-1 cells (r=0.905,P＜0.05) in a concentration-dependent manner.The cell viability was decreased to 27.9％ after exposure to ZnO-NP 20 mg· L-1.Intracellular uptake of ZnO-NP was increased after Ana-1 cell incubated with ZnO-NP at concentrations ranging from 40 to 160 mg· L-1 (P＜0.05).There were obvious free zinc ions in the cells.EDTA 2.5 mmol· L-1 significantly increased the cell viability decreased by ZnO-NP 20 mg· L-1 (P＜0.05).Chelating free zinc ions significantly mitigated ZnO-NP induced cell toxicity (P＜0.05).CONCLUSION Cytotoxicity and apoptosis of Ana-1 cells induced by ZnO-NP might be related to intracellular uptake of ZnO-NP and release of zinc ions.

This study was aimed to investigate the clinical effect of atlantoaxial subluxation with the combination of the muscle tendon manipulation and the modified small angle sagittal pull and conventional Tuina therapy.A total of 80 atlantoaxial subluxation cases were randomly divided into two groups.The cure rate,rate of improvement,imaging and Xray space difference between two groups were observed and analyzed statistically.The results showed that the cure rate was 70.00％ in the treatment group,and 42.50％ in the control group;the total efficiency rate was 97.472％ in the treatment group,and 82.50％ in the control group.There was significant difference between two groups by x2 test.The image of atlanto odontoid anterior space and the side gap difference were significant before and after treatment (P ＜ 0.05).It was concluded that treatment of atlantoaxial subluxation with the combination of the muscle tendon manipulation and the modified small angle sagittal pull achieved better effect compared to the conventional Tuina therapy.This method should be further promoted in the clinical practice.

Objective:To evaluate the detection ability of two kinds of high-throughput method to determine neutralizing antibodies based on a microneutralization test (MNT).Methods:Serum samples were collected from the early phase and follow-up period (117 samples in total) for neutralizing antibody testing. They were tested using MNT, pseudovirus neutralization assay (PBNA), competitive inhibition assay (including enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CLIA)) to evaluate the correlation coefficients and threshold values for the effectiveness of these high-throughput neutralizing antibody assays.Results:The correlation coefficients for PBNA, ELISA, and CLIA relative to MNT were 0.760, 0.778, and 0.725, respectively, for individuals infected with 2019-nCoV. The area under the ROC curve was 0.901 for a cutoff value of 50 for the PBNA assay, 0.934 for a cutoff value of 1∶8 for the ELISA assay and 0.838 for a cutoff value of 1.28AU/ml for the CLIA assay when the threshold value for the microneutralization test was taken as 1: 10 (less than 1: 10 is considered negative).Conclusions:The high-throughput method for the detection of COVID-19 neutralizing antibodies are scientific and feasible, and provide an important technical tool for the regular prevention and control of the epidemic.

BackgroundPrevention and intervention of procrastination in college students are of great practical significance， and studies have illustrated a pairwise correlation among mindfulness， self-control， insecure attachment and procrastination， whereas the mechanism by which insecure attachment leads to procrastination remains unclear， and the related mediation path is quite understudied. ObjectiveTo investigate the effect of insecure attachment on procrastination among college students and the pathway of mindfulness and self-control， so as to inform the design of interventions for procrastination among college students. MethodsRandom and cluster sampling method were utilized to enroll 514 college students from 4 colleges in Guangdong Province From February to April 2023. Subjects were assessed using Irrational Procrastination Scale （IPS）， Adult Attachment Scale （AAS）， Mindful Attention Awareness Scale （MAAS） and Brief Self-Control Scale （BSCS）. Pearson correlation analysis were adopted to identify the correlation among above scales， and the mediation effect was examined via Bootstrap procedure. ResultsAAS score was positively correlated with IPS score （r=0.382， P<0.01）， and negatively correlated with MAAS and BSCS scores （r=-0.242， -0.353， P<0.01）. IPS score was negatively correlated with MAAS and BSCS scores （r=-0.314， -0.682， P<0.01）. MAAS score was positively correlated with BSCS score （r=0.439， P<0.01）. Insecure attachment positively predicted procrastination （β=0.377， P<0.01）， and the prediction of procrastination by insecure attachment was mediated by self-control， with an indirect effect value of 0.163 （95% CI： 0.105~0.223）， accounting for 43.24% of the total effect value. The mindfulness and self-control exerted a chained mediation effect on the relationship between insecure attachment and procrastination， and the indirect effect value was 0.056 （95% CI： 0.028~0.089）， accounting for 14.85% of the total effect value. ConclusionInsecure attachment can influence procrastination among college students both directly and indirectly through the single mediation of self-control or the chained mediation of mindfulness and self-control. ［Funded by 2023 National College Student Innovation and Entrepreneurship Training Program （number， 202310570023）］