The experiment contents were integrated into three parts such as basic skills and verification experiment, systematic experiment and designing experiment. Basic skills and confirmato-ry experiments were performed alone with theory teaching by combination of modern teaching methods and traditional teaching methods, which consisted of “speaking”(experimental principles, methods and main technical points using multimedia), “looking”(demonstrating related operation on teaching website), teachers' demonstration, students' doing experiment independently and summarizing. In this part, the experimental operation skills such as the sterile operation technology, staining technology, microscopy technology and pure culture were emphasized. Systemic experiments would be carried out after completion of the most theory, the experiment time could be adjusted according to the experiment content, and the PBL teaching method was taken in this stage. After the theory teaching of Medical Microbiology was finished, students voluntarily participated in design experiments in the last stage, which were the fusion of scientific research subject and the experimental teaching. From the preview experiment, experiment operation, experiment report, to the final test, the multi-dimensional evalua-tion was implemented throughout the course of experiment teaching.

Objective To explore the prevalence of 11 efflux pumps in isolates of multidrugresistant Escherichia coli(MDR-ECO). Methods Efflux pumps emrB, emrD , emrE, mdfA, sugE, mdtl,tehA, oqxA, qacE△1, qacE and smr-2 were detected by polymerase chain reaction(PCR)in 20 MDR-ECOs isolated from clinical samples. Results Efflux pumps emrB, emrD, emrE, mdfA, sugE, mdtI, qacE △1, tehA and oqxA were detected, and 8 efflux pumps were found in the same strain. Conclusion Multidrug- resistance in Escherichia coli may be related with efflux pumps.

Objective To explore the effect of virtual laboratory (VL) + flipped classroom in teaching of virus infection diagnosis.Methods 40 students of Class One from clinical medical undergraduates of Grade 2014 were randomly taken as the experimental group,with 40 students of Class Two as the control group.The experiment group adopted flipped classroom teaching by virtual lab platform and classroom activities,while the control group adopted traditional classroom teaching such as watching video and lecturing.Finally post-test scores were compared by the independent samples t-test of SPSS 18.0 statistical software between the two groups.The teaching effects were evaluated through questionnaires survey in experimental group.Results The scores (82.73 ± 2.62) of comprehensive assessments were superior to the control scores (57.94 ± 4.65).Difference between the two groups was statistically significant (t=29.380,P=0.000).Students' satisfaction concerning the teaching methods and effects of the flipped classroom in experimental group was up to 85％.Conclusion Flipped classroom based on internet virtual lab platform in teaching of virus infection diagnosis can enhance the teaching quality and improve students' learning enthusiasm and thinking ability.

BACKGROUND: Embryonic stem cells fESCs) develop from early blastular inner cell mass.Under proper condition,ESCs can maintain undifferentiated state in vitro,normal diploid nuclear type,and proliferative potential.In addition,ESCs possess multi-directional differentiation capacity and can differentiate into all sorts of cells of three germ layers. OBJECTIVE: To investigate the feasibility of directed differentiation of ESCs towards thyroid cells in vitro as well as related molecular expression. DESIGN,TIME AND SETTING: A cell-based observational experiment was performed at the Bank of Cord Blood,Second Hospital Affiliated to Sun Yat-sen University between January 2004 and December 2006.MATERIALS: Balb/c pregnant mice at pregnancy 12.5-14.5 days were used for preparation of embryonic fibroblast feeder layer.E14 mouse embryonic stem cell (ESC) strains were gifted by professor Xu from Harvard University.METHODS: Murine El4 ESCs were cultured in methylcellulose semisolid medium to form embryoid bodies (Ebs).These Ebs were transferred for further inductive culture with the stepwise addition of growth factors- thyrotropin (TSH),insulin and kalium iodidum (KI).The cultured thyroid cells of adult Kunming mice were taken as positive control.MAIN OUTCOME MEASURES: ①Cellular morphological change in the process of differentiation.② Detection of expression levels of TSHR,PAX8,TTF-2,and TIF-1 by immunofluorescence assay.③ Detection of expression levels of TSHR,PAX8,NIS,TPO,and Tg by reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: The differentiated cells had clear boundary,exhibiting round,oval,shuttle-shaped,or polygon adhesive growth.On day 6 of inductive ifferentiation,the differentiated cells showed the expression of PAX8,NIS,TPO,Tg,and TSHR,the specific gene of thyroid ceils.On day 8 of inductive differentiation,the expression of TSHR,TIF-1,PAX8,and TIF-2 was detectable in the differentiated cells with morphous similar to thyroid cells.CONCLUSION: ESCs can differentiate towards thyroid cells under given inductive conditions.

Objective To assess the association between rs7597593 polymorphism of ZNF804A gene and schizophrenia,and to assess the relationship between rs7597593 polymorphism and working memory.Methods Schizophrenia patients and healthy controls were diagnosed in accordance with Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-Ⅳ) ; 767 schizophrenia patients and 690 healthy controls were involved.Restriction fragment length polymorphism (RFLP) was carried out to genotype rs7597593 polymorphism.The cognitive function of working memory was assessed by the N-back task.Statistical analyses were carried out with SPSS19.0 software.Results The study found no significantly different genotype frequencies (x2=1.519,P=0.468) and allele frequencies(x2=1.263,P=0.261) of rs7597593 polymorphism between schizophrenia patients and healthy controls,however in the subgroup of higher IQ (IQ ≥ 110),there were significant different distributions of both genotype and allele (x2 =9.411 and 6.529; P=0.009 and 0.011 respectively).It was also found in this subgroup that risk T allele was associated with more error at 1-back task (F=6.854,P=0.009).Conclusion These results indicated that rs7597593 polymorphism was associated with individuals having spared cognitive function; carriers of T allele had worse cognitive function,which maybe a pathway that it contributes to schizophrenia.

Objective To explore the clinical characteristics of rotavirus associated mild encephalopathy/encephalitis with reversible splenial lesion(RAMERS).Methods RAMERS cases were collected from December 2017 to January 2018 at the Department of Neurology,Jiangxi Children's Hospital.The clinical and electroencephalogram characteristics of 14 patients with RAMERS were retrospectively investigated.Data was analyzed by using SPSS 19.0 software.Results Fourteen cases of RAMERS were tested,9 males,and 5 females,with the average age of (27.00 ±6.45) months,and all cases suffered from the generalized tonic-clonic seizures,57.14％ (8/14 cases) had cluster seizure (at lest 2 times/day),convulsions occurred (3.14 ± 1.29) days after gastroenteritis,and 64.29％ (9/14 cases) had pathologic fever (38 ℃ or higher).The background of electroencephalogram(EEG) was characterized by nonspecific rhythmic slow waves in 10 cases (71.43 ％,10/14 cases),normal in 3 cases (21.43 ％,3/14 cases),and interictal EEG performed in 1 case(7.14％,1/14 cases) which was characterized by focal discharges of spikes in the forehead,central,and all of the EEG manifestations go back to normal after 2 weeks.Twelve patients' brain MRI showed solitary splenium of corpus callosum lesion,and two showed splenium of corpus callosum and bilateral symmetry white matter lesion.Conclusions RAMERS is a special type of reversible splenial lesion syndrome,which occurs predominantly in infants and young children.It is characterized by gastroenteritis,benign infantile convulsion,cluster seizure and nonspecific rhythmic slow waves in the background of EEG.Prognosis is usually excellent.Head MRI reexamination is not recommended as a routine procedure to avoid overtreatment.

Objective:To explore whether working memory span training can expand working memory capacity.Methods:A randomized controlled trial design was adopted and a total of 60 healthy college students were recruited and randomly divided into training group ( n=30, receiving adaptive training of spatial breadth task) and control group ( n=30, receiving non-adaptive training of low difficulty spatial breadth task). The cognitive behavior and event-related potential (ERP) data of all subjects when completing the change awareness task were collected before and after training.The SPSS 22.0 statistical software was used for data analysis. The differences between the training group and the control group before and after training were compared by repeated measurement analysis of variance. Results:Repeated measurement ANOVA showed that there were significant time and group interactions at the levels of cognitive behavior(K score, F=5.352, P=0.025) and ERP (CDA, F=4.644, P=0.037) levels. Further post test found that compared with pre-training (pre-test), the K-score ((0.51±0.93), (1.61±1.07), F=26.81, P<0.001) and CDA ((-1.49±1.07)μV, (-2.03±0.94)μV, F=4.731, P=0.041) of the training group increased significantly after training (post-test), and there was no significant difference in K-score and CDA of the control group before and after training (boh P>0.05). Conclusion:Working memory span task can be used as an effective training paradigm to improve working memory capacity.

Objective To set up a living mice colonoscopy platform to establish an orthotopic model of colorectal cancer in mice under direct vision,and to observe its biological behavior such as metastasis.Methods Eighteen-week-old male C57/BL mice were anesthetized,and the intestinal lumen of the mice was examined by a self-developed living mice colonoscopy and Olympus URF-P5 ureteroscopy,respectively.The imaging effects of the two methods were compared.Human colon cancer HT-29 cells were injected into the colonic mucosa of BALB/c-nu mice under direct vision.The colonoscopy was performed on the 3rd,7th and 15th day after the injection to observe the tumor formation in the intestinal lumen.The mice were sacrificed when the body weight decreased significantly or cachexia appeared,and then the abdominal cavity was examined including the tumor formation and metastasis.Results The self-developed living mice colonoscopy platform can provide clear vision of enteric cavity,and no mice died in the colonoscopy examination.In vivo subcutaneous injection of HT-29 cells in mice was performed with a perforation rate of 15％,a mortality rate of 33.3％,a tumor formation rate of 62.5％,an abdominal metastasis rate of 60％,a liver metastasis rate of 25％,and an abdominal wall transfer rate of 25％.Conclusion The self-developed mice colonoscopy platform can be used for the study of colorectum in living mice.The imaging effect is no less than that of Olympus URF-P5 ureteroscopy.In addition,an orthotopic colorectal cancer model can be established by this platform combing with submucosal injection technology.

Objective:To explore the application value of metagenomics sequencing in the etiological diagnosis of bacterial meningitis(BM) in children and improve the diagnosis and treatment effect of BM in children.Methods:All BM cases were collected from Jiangxi Provincial Children′s Hospital from February 1, 2018 to January 31, 2020.Meanwhile, such biological samples as blood and cerebrospinal fluid were collected for traditional etiological testing and metagenomics sequencing.The results of traditional etiological testing were regarded as the gold standard, and the specificity and sensitivity of metagenomics sequencing in the diagnosis of BM in children were confirmed.Results:A total of 45 cases were collected in this study, including 31 males and 14 females, with the age between (74.74 ± 58.67) months.Twenty-six cases were identified by metagenomics sequencing, with the positive rate being 57.78%.Among them, there were 8 cases of Streptococcus pneumoniae, 2 cases of Escherichia coli, 2 cases of Neisseria meningitidis, 2 cases of Staphylococcus, 2 cases of Salmonella, 2 cases of Mycobacterium multiplex, 1 case of Streptococcus intermedius, 1 case of Streptococcus pyogenes, 1 case of Streptococcus paris, 1 case of Streptococcus salivarius, 1 case of Haemophilus influenzae, 1 case of Pseudomonas aeruginosa, 1 case of Acinetobacter baumannii, and 1 case of Aspergillus.The traditional etiological positive rate was 17.78%, and the metagenomic next-generation sequencing (mNGS) positive rate was 57.78% ( P=0.014, kappa=0.273). As per the comparison results, the sensitivity, specificity, positive predictive value, negative predictive value, Youden index and misdiagnosis rate were 100.00%, 51.35%, 30.76%, 100.00%, 51.36%, 48.64% and 0, respectively. Conclusions:Metagenomics examination had high sensitivity, which can improve the etiological diagnosis rate of acute BM in children, especially in case of high clinical suspicion of infection.Therefore, metagenomics examination should be selected as early as possible when the etiology cannot be determined by traditional approaches.

Objective:To analyze the molecular evolutional characteristics of the hemagglutinin and neuraminidase genes of influenza A (H3N2) viruses isolated in Yancheng from 2022 to 2024.Methods:The throat swab specimens of influenza-like illness ( ILI) from sentinel surveillance hospital and outbreak sites were detected using the method of real time Rt-qPCR. The influenza A(H3N2) viruses were isolated using MDCK cells culture method from April 2022 to Marh 2024. The strains isolated from 2022 to 2024 were selected randomly and their sequences of the HA1 and NA genes were amplified through one step RT-PCR method and the PCR products were sequenced.The nucleotide and amino acid site variations and evolutionary characteristics of the genes were analyzed using relevant bioinformatics software. The mutations of genes and nucleic acid locus were analyzed and the evolutional trees were generated using bioinformatics software.Results:A total of 5 020 samples were collected between April 2022 and March 2024, the positive detection rate of influenza virus nucleic acid was 18.59%(933/5 020).The winter and spring influenza peaks were obvious in the two monitoring seasons from April 2022 to March 2024. Among them, the summer influenza peak was obvious in the monitoring season from April 2022 to March 2023, and the H3N2 subtype influenza virus was the dominant epidemic strain in the two monitoring seasons. Genetic evolution tree displayed: the clustering relationships of the respective branches of HA1 and NA genes of 32 strains isolated in Yancheng were basically the same.The HA1 and NA genes of 24 strains isolated from 2023-2024 in Yancheng and the 2022-2024 Northern Hemisphere vaccine strain A/Darwin/9/2021 (H3N2) were located in the 3C.2a1b2a.2a.3a.1 evolutionary lineage, while the 8 strains isolated in the 2022 in Yancheng and the 2021-2022 Northern Hemisphere vaccine strain A/Cambodia/e0826360/2020 (H3N2) were located in the 3C.2a1b.2a.1a evolutionary lineage.The 6 strains (A/JSTH/11735/2023, A/JSTH/11788/2023, A/JSTH/11974/2023, A/JSYD/353/2023, A/JSYD/354/2023, A/JSTH/138/2023) all exhibited variations in the F79L, N122D, P239S, and K276E amino acid sites, which were present in both sporadic and outbreak strains. Because the strains of the antigen epitopes, receptor binding sites and glycosylation sites in the HA1 genes had a certain degree of variations in Yancheng in the 2022-2024 year, the immunogenicity matching between the 24 strains isolated in the 2023-2024 and the Northern Hemisphere vaccine strain A/Darwin/9/2021 was good, while the immunogenicity matching between the 8 strains isolated in the 2022 and the Northern Hemisphere vaccine strain A/Cambodia/e0826360/2022 was good; 32 strains isolated from 2022 to 2024 had no mutations in catalytic residues and drug resistant sites of NA genes.Conclusion:These result indicated that the HA1 and NA genes of influenza A/H3N2 viruses circulated in Yancheng city from 2022 to 2024 are changed gradually.The accumulation of these mutations would result in antigenic drift of influenza A(H3N2) viruses and increase the mismatching of the recommended vaccine strain.Compared with the vaccine strain A/Darwin/9/2021(H3N2), the strains isolated in the 2022 had substantially result in antigenic drift on the whole.The influenza A(H3N2) viruses surveillance should be strengthened to find the new mutant of virus in time.