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Objective:To compare the consistency and detection capability of seven 2019-nCoV nucleic acid detection kits, and provide reference for detection method selection of clinical laboratory and diagnosis of new coronavirus pneumonia.Methods:Two batches of pharyngeal swab samples were collected from tenpatients with confirmed infection of 2019-nCoV and 10 suspected patients with negative 2019-nCoV test results during January 29 to February 5, 2020 in Shenzhen Luohu People′s Hospital. Seven kinds of kits were labeled as ato g and used for nucleic acid detection respectively to evaluate the consistency of the test results of the clinical samples. A 2019-nCoV positive specimen was selected and diluted to 5-concentration gradient plates (Level-1 to 5) with RNase-free water. The positive detection rate and intra-batch repeatability of different brands of kits were compared.Results:The negative and positive coincidence rates of twenty clinical samples tested by six kinds of kits were 100%, and the positive and negative coincidence rate was 8/10 and 10/10 for the other kit, respectively. The results of intra-batch repeatability showed the CVs of viral loads tested by these seven kits were all less than 5%. In the concentration range of Level-1 to 3, the detection capability for open reading frame (ORF)1ab gene of Kit b,d and f was lower than Kit a,c,e and g, and the detection capability of kit e and g was the highest (14/15). The detection capability for N gene of Kit a (15/15) was higher than the other 5 kits. The comprehensive analysis of the detection capability for ORF1ab and N gene showedthat Kit d had the lowest detection capability (ORF1ab:40%,N:53%), and there was no significant difference in the detection capability of Kit a, b, c, e, and f.Conclusions:There was no significant difference in the accuracy and repeatability of the seven kits for positive samples with high viral loads, and the detection performance was good; but some kits had poor detection capability for weak positive samples. It is suggested that the weak positive samples should be rechecked by at least two manufacturers′ kits to ensure the accuracy of the results.
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We analyzed the antimicrobial resistance and pulsed field gel electrophoresis (PFGE) patterns of Salmonella strains of infectious diarrhea isolated four hospitals in Shenzhen during 2012-2016.A total of 137 Salmonella strains collected in 4 hospitals in Shenzhen were identified by serotyping,micro-dilution method was used to detect the antimicrobial susceptibility of the isolates.Pulsed field gel-electrophoresis(PFGE) was used for molecular typing and cluster analysis of S.typhimurium and S.enterica strains.Results showed that 137 strains of Salmonella were divided into 30 kinds of serotype.S.typhimurium was the predominant serotype.The drug susceptibility test indicated that the antibiotic resistance of the strains to chloromycetin,ampicillin and amoxicillin were more serious than other drugs,the resistance to penicillins,cephalosporins,aminolycosides and macrolides showed increase trends year by year.Of 49 strains of S.typhimurium were divided 38 molecular patterns by PFGE,with similarity ranged from 65.5％ 100％,TY18 was the main PFGE pattern.The 27 strains of S.enterica were divided into 7 molecular patterns by PFGE,with similarity ranged from 61.8％-100％,EN7 was the main PFGE pattern.The status of drug resistance of infectious diarrhea isolates was rather severe,PFGE patterns showed diversity,suggesting the diarrhea cases were distributed sporadically.Partial PFGE patterns and its corresponding antidrug spectrum have certain aggregation relationship.
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Objective To understand the prevalence and risk factors of Enterobius vermicularis among preschool children in kindergartens in Luohu District Shenzhen City. Methods A total of 489 children in 6 kindergartens were selected by the stratified sampling method and investigated for E. vermicularis infection by the cellophane anal swab technique. The information of sanitary condition of the kindergartens personal hygiene and family hygiene were investigated by questionnaire. Results The infection rate of E. vermicularis was 10.2% 50/489 . The single factor analysis indicated that the following factors might re?lated to the infection the different classes of kindergartens grades ground of bed room private toilet types of taps and beds bed management education levels of parents frequency of shower and washing anus and washing hands before meal and after WC. The multivariate Logistic analysis indicated that the bed management education level of mothers frequency of washing anus and private toilet were independent risk factors for E. vermicularis infection. Conclusion To control the infection of E. vermicularis the circumstance and management of kindergartens parents knowledge of E. vermicularis infection and chil?dren s healthy habit need improve.
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Objective To analyze the complete genome sequence of a Shenzhen coxsackievirus A2 strain CVA2-SHZH13-01 and its evolution.Methods RT-PCR was used to amplify the complete genome of CVA2-SHZH13-01 strain.The PCR products were purified and sequenced to analyze their genetic character-istics.Results The complete genome of CVA2-SHZH13-01 strain was 7400 bp in length, encoding 2191 amino acids.CVA2-SHZH13-01 strain was highly similar with the novel recombinant CVA2-HK (431306) strain isolated from Hong Kong sharing the nucleotide homology of 98.3%, 98.8%, 99.0%, 99.2%, 98.8%and 98.9%in 5′UTR, P1 ( VP1 to VP4) , P2, P3, 3′UTR regions and complete genome, respec-tively.CVA2-SHZH13-01 strain was highly identical to the international standard strain CVA2-Fleetwood showing the homology of 81.6% in nucleotide sequences in P1 region, but closely associated with EV71-SHZH03 and EV71-GD2009 strains (82.8%-88.7%) in P2 and P3 regions.The phylogenetic analysis in-dicated that CVA2-SHZH13-01 strain belonged to the CVA2-HK (431306) variant.Data from analysis of amino acid in P1 region showed that there were three amino acid mutations in CVA2-SHZH13-01 strain including aa5L→F, aa666S→G and aa671T→I as compared with CVA2-HK (431306) strain.Conclusion CVA2-SHZH13-01 strain belonged to CVA2-HK (431306) variant.
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Objective To investigate correlation between demyelination and caspase-12 expression alteration after compressed spinal cord injury (CSCI) so as to discuss mechanism of demyelinating lesion after CSCI.Methods Seventy-five adult SD rats were randomly divided into five groups,ie,normal group,control group,compression 1 d,3 d and 7 d groups,with 15 rats per group.Models of spinal cord compression were established with a self-made device.Ultrastructure of the demyelinated nerve fibers was observed by electronic microscope and oligodendrocyte apoptosis was detected by TUNEL staining and double labeling immunofluorescence.Immunoblotting was used to defect caspase-12 that was related to cell apoptosis.Results Demyelination of nerve fiber occurred after CSCI and was aggravated with time.Apoptosis of oligodendrocytes was found after CSCI,and showed significant difference between compression 7 d group and normal group (P ＜ 0.05).Caspase-12 was also upregulated with extension of compression time.Conclusion Caspase-12 mediating oligodendrocyte apoptosis is one of the mechanisms of nerve fiber demyelination after CSCI.
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Objective To observe the effects of electro-acupuncture on the expression and inhibition of DNA binding protein 2 (Id2) and myelin basic protein (MBP),and to explore the mechanism of remyelinization after compressive spinal cord injury (CSCI) in rats.Methods Fifty-four SD rats were randomly divided into a control group and a treatment group,and each was further subdivided into 3 time point subgroups:3,7 and 14 days.There were 9 rats in each subgroup.The CSCI models were made with a self-designed method.The acupuncture points Jiaji (EX-B2),bilateral Zusanli (ST36) and Taixi (KI3) were selected for treatment.Electro-acupuncture (continuous wave,2 Hz,1.5 V)was applied to the bilateral Zusanli (ST36) and Taixi (KI3) points.The control group received the injury but no treatment.The changes in the ultrastucture of the nerve fibers＇ white matter were de-termined by transmission electron microscopy (TEM).The alterations in the expression of MBP and Id2 were observed by double labeled immunofluorescence and Western blotting on the 3rd,7th and 14th day after the injury.Results TEM showed that the myelin sheaths in the control group had degenerated,swollen,and even broken down after CSCI.Changes to the myelin sheaths in the treatment group were milder than those in the control group.The immunofluorescence results showed the amount of Id2-immunoreactive oligodendrocytes in the control group to be (20 ±2) on the 3rd day after CSCI,becoming (16 ± 1) on the 14th day.The differences among the 3 control subgroups were not statistically significant.The amount of Id2-immunoreactive oligodendrocytes in the treatment group was (13 ± 1) on the 3rd day,reaching a minimum the 14th day.The differences among the 3 treatment groups were statistically significant.The differences compared with the control group at the same time points were also statistically significant.Western blotting showed that the expression of Id2 in the contrast and treatment groups was (1.12 ±0.12) and (0.67 ±0.01) respectively on the 3rd day after CSCI,and both decreased with time.The expression of Id2 in both groups reached their minima ((0.86 ±0.02) and (0.25 ±0.01) respectively) on the 14th day.The difference between the treatment groups and the contrast group was statistically significant at each time point.The expression of MBP in the contrast and treatment groups at day 3 was (0.44 ± 0.02) and (0.67 ± 0.04) respectively,and these increased with time.The expression of MBP in both groups peaked at the 14th day (at (0.95 ± 0.04) and (1.74 ± 0.09) respectively).These differences were again statistically significant.Conclusion Electro-acupuncture can regulate the expression of Id2 and MBP after CSCI.The down-regulation of Id2 which controls MBP negatively and the up-regulation of MBP may contribute to remyelination in the injured spinal cord.
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It is extremely necessary and important for colleges or universities to transform the education concepts that barricade students' initiative and creativity, especially the one that takes fi-nal examinations as sole standard to evaluate teaching and learning effects. In order to display and cultivate students' study ability more comprehensively, we manage to establish a set of formative eval-uation system for regional anatomy course , which involves tests and examinations and evaluations throughout the whole teaching and learning process. It solves the long-lasting problem that examina-tions are final purposes of teaching and learning, and thus, teaching values not only results but also learning process, which directs students' attention to conventional studies and helps develop good study habits, greatly reducing the randomness of final academic performances. The diverse assessment methods, along with accumulated assessment results, can improve students' learning effects through-out the whole semester. The fundamental purpose of this system is to inspire students' passion for study and creativity and monitor the teaching process.