OBJECTIVE To compare the cleaning effect of the dentistry high speed turbine wheel handset by the three purging methods,i.e.,manual,the entire automatic ultrasonic wave and the entire automatic hot cleaner/sterilizing machine.METHODS The Staphylococcus aureus was used to pollute dentistry handset,then the quota sterilization experiment was carried out.RESULTS 99.47%,99.80%,and 99.99% of the extinguishing rate were got by the manual,the ultrasonic wave cleaner and the entire automatic hot cleaner/sterilizing machine purging methods respectively,after the SPSS13.0 variance analysis,P

To prepare the polyclonal antibody against the 3D polymerase of foot and mouth disease virus (FMDV), the 3D polymerase gene of this virus was amplified by PCR and doubly digested with BamH I and Nde I. Then, it were cloned into expression vector pET-30a(+) to obtain the recombinant plasmid pET-3D and this plasmid was transformed to E.coli BL21(DE3) with induction by IPTG.The target protein was identified and purified with SDS+PAGE, and the inclusion bodies were extracted. The purified target protein was used as antigen to immunize New Zealand rabbits to prepare the polyclonal antibody against 3D polymerase of FMDV, which was then characterized by indirect ELISA and Western blotting. As demonstrated by SDS-PAGE, the target protein with a molecular weight at 46 ku was expressed. The polyclonal antibody showed high affinity and obvious specificity and its titer was above 1:8 000. This polyclonal antibody may lay a foundation for the further studies on the biological functions and epitopes of the 3D polymerase of FMDV.

Objective To analyze the different metabolites of the classical activated (M1) ,alternatively activated (M2) and resting BV2 cells by metabolomics method .Methods The mRNAs of several potential biomarkers were determined by real-time PCR analyses to confirm the state of BV2 cells .Static GC-MS combined with metabolomics technology was used to analyze the metabolic changes .Results There were 15 biomarkers identified between the M1 group and the resting group ,and 15 biomarkers were found in the M2 group and the resting group .Conclusion The present study provides an effective way to reveal the mechanism of the polarization of BV 2 cell ,and it might provide a theoretical basis to prevent or treat the neurodegen-erative diseases .

Objective To analyze the distribution of various genotypes of human cytomegalovirus glycoprotein N ( HCMV gN) in patients with HIV infection; to investigate the effects of HCMV-HIV co-in-fection on disease progression and the relationships between HCMV gN genotypes and disease progression. Methods Patients with active HCMV infection were screened out from 359 patients with HIV infection by using the pp65 antigenemia assay.The genes encoding HCMV gN ( UL73 ) were amplified by nested PCR ( nPCR) .The amplicons were digested by restriction enzymes including MboⅠ, ScaⅠ and SalⅠ.Then, the restricted fragment length polymorphisms were further analyzed on 4%agarose gel.The relationships be-tween HCMV genotypes and the morbidity and mortality of acquired immune deficiency syndrome ( AIDS ) were investigated via a prospective study.Results Among the 359 patients with HIV infection, 28 subjects were positive for the HCMV pp65 antigenemia assay.The HCMV gN genotypes in 20 patients with active HCMV infection were distributed as: gN-3a (4/20, 20%), gN-1 (4/20, 20%), gN-4d (1/20, 5%), gN-4b (1/20, 5%) and mixed infection (10/20, 50%).Patients with HCMV-HIV co-infection were more likely to develop AIDS during the follow-up period (RR=9.78).Patients harboring HCMV gN-1 and gN-4 genotypes would seem likely to have 4.6 times of chance leading to AIDS-associated death than those harbo-ring other HCMV gN genotypes.Conclusion HCMV infection ( especially gN-1 and gN-4 genotypes) might accelerate the progression of HIV infection.

Feces and intestinal contents of pigs suspected with porcine epidemic diarrhea virus were collected from a farm in Minqin County,Gansu Province,China.After the suspected positive sam-ples were detected by RT-PCR,Vero cells were used to isolate and culture them in vitro.The suc-cessfully isolated virus was identified in the laboratory,and its whole genome sequence was ana-lyzed for genetic evolution.The pathogenicity was evaluated by animal regression test.The results showed that typical syncytial lesions could be observed when the PEDV-positive treatment solu-tion was inoculated with Vero cells in the 4th generation,and the virus titer in the 6th generation reached 10-4 75TCID50/mL.PEDV-like virions with a diameter of about 100 nm and a round shape with obvious capsular membranes and spikes were observed by electron microscopy.Whole genome sequencing analysis showed that the total length of this strain was 28 085 bp,which was far from the G1 subtype represented by the classical strain CV777(96.6％),and had a high homology with the G2b strains BC-2011-1,IA1,USA/Colorado/2013 and WELL(98.6％).This indicated that the strain belonged to the G2b epidemic strain.The animal regression test showed that the 5-day-old piglets developed vomiting,acute watery diarrhea,emaciation and mental depression within 12 h after the attack,and the symptoms worsened and died within 24 h.After autopsy,the infected piglets could be observed with stomach swelling,high intestinal heave,thin and transparent intesti-nal wall,and undigested milk clots inside.In summary,a PEDV G2b epidemic strain was success-fully isolated and identified in this study,and its whole genome sequence and pathogenicity were analyzed,providing research materials for future studies on PEDV gene function,pathogenic mech-anism and vaccine development.

ObjectiveTo describe a COVID-19 outbreak due to SARS-CoV-2 Omicron variant in a school and provide suggestions for COVID-19 prevention and control. MethodsData on the COVID-19 outbreak in a school in Putuo District of Shanghai were collected from November 14 to December 20， 2022. Epidemiological characteristics， incidence rate of secondary cases and response measures were described and analyzed. ResultsA total of 27 COVID-19 cases were identified infected with SARS-CoV-2 Omicron BA.5.2 variant， including 14 students （51.9%） and 13 family members / teachers living with those students （48.1%）. The first case occurred on November 14， with peak incidence during November 16-18. The median generation interval of the second generation cases was 2 （2，3） days. The index case （case 1， a student） had a clear contact history outside the school， which was found through routine examination in key populations in the school. Immediate management was conducted after the notification. All the second generation cases were exposed students in the same class with case 1， which were identified during the quarantine， whereas the third generation cases were their family members/teachers living with the second generation cases. The incidence rate within the class and school were 36.8% and 3.0%， respectively. No further social transmission was found outside the school. ConclusionEarly detection， multi-sectoral collaboration， prompt control and quarantine measures are effective in containing SARS-CoV-2 transmission. Health promotion， surveillance， ventilation and prophylactic disinfection should be reinforced in schools， office buildings and other gathering places.

Objective:To record occlusal contact of primary dentition at maximal intercuspal position in children with individual normal occlusion.Methods:A total of 57 children were recruited from patients of the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. Inclusion criteria were that the subjects were 3-5 years old with no visually detectable caries or pupal and periapical diseases, had complete primary dentition, had individual normal occlusion, had normal function of craniofacial system, were medically healthy, could cooperate with sampling and had obtained written informed consent from the parents or guardians. Finally, forty-seven children aged 3 to 5 years old were enrolled, including 24 males and 23 females. The age, height and weight of all subjects were (4.1±0.7) years old (ranging 3.0-5.8 years old), (103.7±7.2) cm (ranging 90-120 cm) and (17.1±2.5) kg (ranging 12.5-22.5 kg), respectively. Occlusal abilities such as occlusal contact area, average bite pressure, maximum bite pressure, maximum bite force and occlusal balance were measured with Dental Prescale Ⅱ system.Results:Maximum bite force and occlusal contact area at intercuspal position in children with primary dentition were (567.40±223.84) N (ranging 226.7-1 154.6 N) and (18.56±6.54) mm 2 (ranging 8.4-41.2 mm 2), respectively. There was a significantly strong correlation between maximum bite force and occlusal contact area ( r=0.954, P<0.01). Height and weight of children were also positively correlated with their maximum bite force ( r=0.397, P=0.022 and r=0.453, P=0.008, respectively). Maximum occlusal bite force and contact occlusal area of boys [(651.80±224.34) N and (20.77±6.97) mm 2] were significantly higher and larger than those of girls [(479.34±190.45) N and (16.25±5.27) mm 2] ( P<0.05). Thirty-two of all 47 children had one occlusal contact point with maximum bite pressure, mostly locating within the primary molar region. Bite forces of anterior and posterior teeth of primary dentition were (124.12±56.99) N and (450.11±205.09) N, respectively, about (21.82±11.40)% and (71.80±21.35)% of maximum bite force of the whole primary dentition. All of the occlusal balance points located in posterior teeth regions. Occlusal contacts were observed at both anterior and posterior teeth of primary dentition with individual normal occlusion. Conclusions:There was a great variation of maximum bite forces of primary dentitions at intercuspal position of children with individual normal occlusion. Maximum bite force of primary dentition was significantly correlated with occlusal contact area, height and weight of children. Occlusal contact points with maximum bite pressure and occlusal bite balance points of primary dentitions mostly located in primary molar regions.