0.990 0) with an average recovery ranged from 86.1% to 109.0%.The injection RSD were within 0.84%～3.1%(n=6).CONCLUSIONS:The method is successfully applied for simultaneous determination of 22 kinds of free amino acids.

Objective To construct eukaryotic enhanced green fluorescent protein (EGFP) expressing recombinant plasmid, pEGFP-C1-hnRNP A1, which contains coding sequence of human hnRNP A1 (heterogeneous nuclear ribonucleo-protein A1), and to perform cellular localization analysis of EGFP tagged hnRNP A1 under stress. Methods Total RNA was isolated from HeLa cell used for synthesis of first-strand cDNAs using reverse primers that are specific for the 3′-un-translated region of hnRNP A1. hnRNP A1 gene fragments were then amplified by touch-down PCR from those cDNAs and inserted into pEGFP-C1 fluorescent bearing vector through EcoRⅠ/BamHⅡdouble enzyme digestion and T4 DNA Ligase connection. The recombinant pEGFP-C1-hnRNP A1 plasmid was transfected into HeLa cells and green fluorescent tagged fusion proteins was examined by Western blot and confocal fluorescence microscopy. Co-localization of EGFP-hnRNP A 1 with poly (A)+mRNA (the marker of the stress granules), or DCP1a (the marker of processome) were detected by RNA fluores-cence in situ hybridization and immunofluorescence. Results The pEGFP-C1-hnRNP A1 was sequenced and digested cor-rectly by restriction single/double enzyme. The green fluorescent fusion protein was also detected in transfected HeLa cell by Western blot and confocal fluorescence microscopy. EGFP-hnRNP A1 co-localizes with poly(A)+mRNA, but not DCP1a. Conclusion Recombinant eukaryotic plasmid of pEGFP-C1-hnRNP A1 was constructed successfully and expressed effec-tively. EGFP tagged hnRNP A1 takes part in forming stress granules.

Background To explore the relationship between polymorphism of APOE gene in traumatic brain injury(TBI)patients suffering from traffic accident and the outcome of TBI.Methods TBI patients were randomly selected in this study with caxe-wntrol trial. The genotype of APOE allele was tested by a polymerase chain reaction-restriction fragment length polymorphism ( PCR-RFLP), and the association between different genotypes of APOE alleles and outcome of TBI patients, were analyed.Results In TBI group frequency of APOE ε2 allele was 0. 1010, and frequency of APOE ε2/ε3 was 0. 1596.Both of these results were significantly higher than that in normal people (APOE epsilon 2 was 0. 0050, APOE ε2/ε3 was 0. 0100) (P＜0.05). Frequency of APOE ε2 and APOE ε2/ε3 in TBI group who died was 0. 1970 and 0. 2727. These were significantly high compared to TBI patients who had good recovery.Conclusions APOE allele ε2 and APOE genotype ε2/ε3alleles indicate a poor prognosis of traumatic brain injury patients.

Objective: To investigate the social support of medical students during the outbreak of COVID-19 and its mediating effect on the correlation between epidemic exposure and depression with anxiety. Methods: A total of 5 593 medical students were enrolled, and Social Support Rating Scale(SSRS), Patient Health Questionnaire-9 and 7-tiem Generalize Anxiety Disorder Scale were used to measure. Results: The social support score of SSRS of male students was lower than that of female students (t=-4.36, P<0.05) and juniors and seniors scored lower than other grades(F=4.84, P<0.05). Epidemic exposure proportion was positively correlated with both depressive proportionand anxiety proportion(r=0.05, 0.06, P<0.01), while epidemic exposure and depressive proportion and anxiety proportion were negatively correlated with social support score(r=-0.05, -0.25, -0.19, P<0.01). After controlling for gender and grade, the mediating effect of social support in the correlation between epidemic exposure and depression accounted for 26.6% of the total effect, and the mediating effect of subjective support and supportive utilization was 32.3% and 25.7% respectively. After controlling for gender and grade, the mediating effect of social support in the correlation between epidemic exposure and depression accounted for 20.0% of the total effect, and the mediating effect of subjective support and supportive utilization was 15.9% and 12.2% respectively. Conclusion Social support has partially mediating effect in the correlation between epidemic exposure with depression and anxiety.

Objective To construct eukaryotic Flag (DYKDDDDK) expressing recombinant plasmids, pCMV-N-Flag-SND1-No1/2, which contain the coding sequence of human SND1-No1(from 1st AUG)or SND1-No2 (from 2nd AUG), and perform the cellular localization analysis of Flag-tagged SND1-No1/2 under stress condition to study the function of the two AUG in the SND1 containing stress granules formation. Methods The gene fragments of SND1-No1/2 were amplified by PCR from the whole SND1 transcript and inserted into pCMV-N-Flag expressing vector through BamHI/EcoRI double en-zyme digestion and T4 DNA Ligase connection. The recombinant pCMV-N-Flag-SND1-No1/2 plasmids were transfected in-to HeLa cells and the expression of Flag-SND1-No1/2 fusion proteins was examined by Western blotting assay. Immunofluo-rescence assay was performed to detect the co-localization of Flag-SND1-No1/2 with endogenous SND1 granule. Results The pCMV-N-Flag-SND1-No1/2 were sequenced and digested correctly by restriction single/double enzyme. The Flag-tagged SND1-No1/2 fusion proteins were also detected in transfected HeLa cell by Western blotting assay. Both of them showed the co-localization with endogenous SND1 granule. Conclusion The recombinant eukaryotic plasmids of pCMV-N-Flag-SND1-No1/2 were constructed successfully and expressed effectively. The depletion of 1st AUG failed to af-fect the formation of SND1 containing stress granules.

OBJECTIVE Alzheimer's disease(AD)is the most common neurodegenerative disease worldwide.Neuroinflammation is a potential target for the patients with AD.It is attributed to activated microglia and the release of various inflammatory mediators from infec-tion,ischemia and toxin accumulation.Accumulating evi-dence has indicated that the cGAS-STING pathway driven neuroinflammation in neurological disease.TSG is a main natural active ingredient that derived from polyg-onum multiflorum.Previous research from our group found that TSG has beneficial effects of anti-aging,anti-inflammatory action and improving memory function in APP/PS1 transgenic AD mice.Here,we investigated the effects of TSG on cognitive impairment and neuroinflam-mation in APP/PS1-AD mice and explore the underly-ing mechanism by which TSG ameliorates memory func-tion in the cGAS-STING-mediated inflammatory response.METHODS The Morris water mace test and the novel object recognition test were performed to test the effects of TSG on spatial learning and cognitive and memory abil-ity in APP/PS1 double transgenic AD mice model.In addi-tion,real-time quantitative PCR,Western blotting,ELISA analysis,and flow cytometry to examine gene and pro-tein expression of cGAS-STING related pro-inflammatory cytokines and chemokines.Statistical analyses were ana-lyzed using the SPSS 25.0 package by analysis of vari-ance(ANOVA).Neuman-Keuls or Tukey's multiple-com-parisons test were conducted as ANOVA justified post hoc comparisons between group means.RESULTS We demonstrated that AD transgenic mice exhibited cognitive deficits accompanied by the elevated serum and brain inflammation.The expressions of serum inflammatory cytokines and the activation of microglia in cerebral cor-tex and hippocampus were suppressed after TSG treat-ment,which was probably attributable to the decrease of cyclic GMP-AMP synthase(cGAS)and stimulator of interferon genes(STING)triggered immune response.Additionally,the data showed that TSG treatment reduced the expression level of inflammatory cytokines(IL-1β,TNF-α,IFN-β,IFN-α)in microglial cells BV2 primed with LPS and IFN-γ.CONCLUSION TSG implicated the health benefits in preventing cognitive disorders by inhib-iting neuroinflammation via cGAS-STING signalling path-way in AD.