Objective To explore the concentration of required residual available chlorine dioxide(ClO 2 )and optimun contact time for ClO 2 disinfection in order to ensure the microbiological indexes of waste water of hospital disinfected by ClO 2 qualified.Meth ods The waste water samples collected from hospital,to which were aritificially added with predetermined con-centrations of bacteria,were disinfected by various concentrations of ClO 2 (2?4?6?8?10?12mg /L)with various contact time (5?10?30?60?90min).After disinfection,the concentration of residual ClO 2 and the contents of microorganism in waste water samples were determined.Re sults After30-min disinfection by10.0mg /L ClO 2 ,the waste water sample originally containing1.52?10 2 /L E.coli showed a bactericidal rate of99.99%and a concentration of residual ClO 2 at2.5mg /L.After10-min disin-fection by10.0mg /L ClO 2 ,the waste water samples originally containing1.12?10 10 /L Salmonella showed a bactericidal rate of100%and a concentration of residual ClO 2 at2mg /L.After5-min disinfection by10.0mg /L ClO 2 ,the waste water samples o-riginally containing M.tu berculosis at concentration of++++showed a negative result and a concentration of residual ClO 2 at3.5mg/L.Conclusion After the primary treatment,ClO 2 disinfection with contact time of30minutes and a residual concentration of ClO 2 at2.5mg /L could ensure the germicidal effect for E.coli,Salmonella and M.tu berculosis in waste water of hospital qualified.

This paper discusses the definition , classification, selection, monitoring and evaluation of animal biosafety isolation device .Evaluation order of animal biosafety isolation device follows animal survival needs -biosafety needs-animal welfare requirements .

ObjectiveTo investigate the developmental status and their relationship of self-supporting personality and career maturity of medical students.Methods450 medical students were surveyed by self-supporting personality scale and career maturity questionnaire.Descriptive statistical analysis,t-test,correlation analysis and regression analysis were used to do data analysis.Results ( 1 ) Most dimensions of self-supporting personality such as personal initiative,interpersonal initiative,interpersonal flexibility and personal responsibility were positively related to the career maturity ( r=0.53,P＜0.01 ; r=0.49,P＜0.01; r=0.46,P＜0.01 ; r=0.45,P＜ 0.01 ).(2)Career maturity of medical students can be positively predicted by several dimensions of self-supporting personality ( R2 =0.49,F=60.10,P＜ 0.01 ).ConclusionThe career maturity of medical students is closely associated with their self-supporting personality.

Objective To identify the significance of neuropsychological single-item scales in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD).Methods A total of 676 elderly people living around Dongzhimen district in Beijing were recruited using multistage sampling method.Cognitive function was assessed by minimum mental state examination (MMSE)and other scales.MCI was diagnosed based on the criteria proposed by Petersen (1999),and AD was diagnosed based on the NINCDS-ADRDA.Subjects were divided into normal cognitive group (n=213 cases,31.5％),Alzheimer's disease (AD) group (n=167 cases,24.7％),amnestic mild cognitive impairment (aMCI) group (n=186 cases,27.5 ％) and non-AD dementia group (110 cases,16.3 ％).Results The MMSE scores in AD,aMCI and normal groups were 23.0 ± 5.9,25.9±2.6,8.1 ± 1.7,respectively.There were significant differences in MMSE scores between AD,aMCI and NC groups separately (all P＜0.01).Compared with MCI and NC group,th scores of time orientation,attention,calculation and immediate recall and delayed recall were significantly decreased in AD group (all P＜0.01).Comparing with normal group,the scores of attention and calculation were reduced in aMCI group (both P＜0.01).The delayed story recall (DSR) scores in AD,aMCI and NC groups were 15.7 ± 11.7,7.6 ± 4.9,26.5 ± 9.3,respectively.There were significant differences in mean DSR scores between AD,aMCI and NC groups separately (all P＜0.01).Compared with normal group,the clinical dementia rating (CDR) scores were higher and the mean clock drawing task (CDT)scores were lower in AD and aMCI groups (both P＜0.01).Conclusions Both neuropsychological assessment tools such as MMSE and single-item scales such as delayed story recall have the certain significance in the diagnosis of MCI and AD.

Objective To screen the effective silencing targets of P21 gene at the cellular level in rhesus monkey . Methods To detect the expression of P21 gene in COS-7 cells ( derived from the kidney of African green monkey , Cerco-pithecus aethiops).Four small hairpin RNA (shRNA) sequences targeting rhesus monkey P21 gene were designed and in-serted into lentivirus-based gene silencing constructs FUGW-TDT.The vectors were transfected into COS-7 cells respective-ly.The suppression of P21 mRNA was detected by real-time PCR, and the expression of P21 protein was detected by West-ern blot assay .Results Four gene-silencing sequences were screened that lied in 541-561 bp, 542-562 bp, 215-239 bp, and 624-648 bp of the rhesus monkey P21 mRNA.Their silencing rate was (91.82 ±3.21)%, (82.47 ±2.48)%, (81.31 ±2.69 )% and ( 87.35 ±4.59 )%, and the protein expression was ( 11.97 ±0.70 )%, ( 20.22 ±0.65 )%, ( 23.21 ± 0.63)%and (14.42 ±0.86)%, respectively.Conclusions Four effective silencing target sequences are screened at cel-lular level , which can be used in gene silencing research of rhesus monkeys .

BACKGROUND: Recently, one focus of research has been Annexin Ⅴ (AnV) existing on hepatic cells membranes as a fundamental receptor related to hepatitis B virus (HBV) infection. Also its expression in placental tissues has been a matter of debate. The study of the relationships between placental cells infected with HBV and their AnV expression will be of great value in future prevention strategies and treatments.OBJECTIVE: To investigate the presence of AnV in HBV infected human's placental cells and its potential role in HBV intrauterine transmission.DESIGN: Randomized controlled experiment.SETTING: Taishan Medical College.MATERIALS: Placental tissue was collected from HBsAg positive full term pregnant women (30 cases) admitted to Jinan Institute for Maternal and Child Health, Taian Central Hospital and Taian Institute for Maternal and Child Health from January 2003 to December 2004. Maternal serum was also obtained. Informed consents for participating in this study were obtained from all the involved pregnant women and this experiment was approved by the Hospital Ethics Committee. Rabbit-anti-human AnV purified affinity antibody (first antibody), rat-anti-human HBs mAb (first antibody),and biotinylated goat-anti-mouse IgG (secondary antibody) were supplied by Wuhan Boster Bioengineering Company.METHODS: Using SABC immunohistochemical staining reagent, 18 HBsAg positive placentas were obtained from 30HBsAg infected patients in full term pregnancy. These were considered as the positive group and the other 12 were used as negative controls. The staining process included dewaxing, dehydration of embedded slides and microwave antigen restoration. In the wet box, rabbit-anti-human AnV purified antibody (first antibody, 1:60, monoclonal antibody)was added on the slides and kept at 4 ℃ overnight. Rat-anti-human antibody HBs mAb(secondary antibody, 1:50) was added and kept at 4 ℃ ovemight, after this procedure, biotinylated goat-anti-mouse IgG(1:100), the first fluorescent antibody such as FITC-goat anti-rabbit IgG (1:50) and the second fluorescent antibody (Avidin-Cy3) were used,respectively. The slides were sealed with buffered glycerol and examined under a confocal laser scanning microscope.The images on the slides were analyzed with IPP 4.5 image programs.MAIN OUTCOME MEASURES: Detecting the simultaneous existence and distribution of HBsAg/AnV in placental cells with HBV infection.RESULTS: Ten cases from the positive group were simultaneously detected for HBsAg/AnV by double-labeled immunofluorenscence assay and confocal laser scanning microscope. AnV expression was detected in the trophoblastic, interstitial cells and vascular endothelial cells of villi interstitial blood vessels, and the coexistence of HBsAg/AnV was found even in one cell.CONCLUSION: HBsAg combined with the receptor AnV in the same placental cells is a common finding in HBV infected full term pregnant women. This finding is very suggestive of a mechanism where AnV could promote hepatitis B virus to enter the placental cells and cause intrauterine infection.

Objective To evaluate the femur biomechanical changes of finite analysis with different femoral stem ex-tension implants in total knee arthroplasty (TKA). Methods The full-length femoral CT scan was performed in selected healthy volunteers. The femoral digital model was established with Mimics 10.0 and Geomagic Studio 10.0 software. The models of femoral prosthesis and stem extension implant were created by laser scanner. According to the common three hip loading modes (1 586 N, 1 690 N and 2 132 N), the maximum principal stress (MPS), the maximum principal elastic deforma-tion (MPES) and MPES distribution changes were recorded and analyzed by three-dimensional finite element analysis with ANSYS Workbench13.0 software. Results The MPS values before TKA were 98.54, 147.36 and 143.51 MPa respectively when values of femoral head loading were 1 586 N, 1 690 N and 2 132 N. With the increase in the length of the femoral pros-thesis extension rod, the MPS and MPES showed a decreasing trend. There was a positive correlation between free femur ra-tio (FFR) and MPES (P<0.05). The MPES distribution was gradually concentrated at the top point of femur stem extension implant with the increase in the length of the femoral prosthesis extension rod. Conclusion The values of MPS and MPES were gradually decreased with the increase in the length of the femoral stem extension implant. There was a positive linear correlation between FFR and MPES. The stress concentration was focused obviously at the top end of femoral stem extension implant with its length more than 120 mm.

Objective To decrease the p53 gene expression at cellular and animal levels in marmoset using RNA interference technique.Methods The shRNA interference sequences were designed and inserted into the adeno-associated virus vector plasmid after bioinformatics analysis.The plasmids were transfected into African green monkey kidney cos-7 cells.The suppression of p53 mRNA was detected by real-time PCR, and the changes of p53 protein expression were detected by Western bolt.The adeno-associated virus-8 was injected through the hind leg vein.The changes of p53 protein expression in the liver tissue was detected by Western blot and immunohistochemistry.Results We screened two RNA interference effective arget sequences.The expression of p53 mRNA was suppressed ( 82.7 ±8.1 )% and ( 80.7 ± 7.5)%, respectively (P<0.05), and the expression of p53 protein was decreased (77.3 ±11.5)% and (73.7 ± 10.7)%, respectively (P<0.05).The two marmosets after virus infection showed that there were virus distributions in the liver, testes, and neck detected by in vivo fluorescence imaging.The expression of p53 in the marmoset liver was detected by western blot, immunohistochemistry analysis showing no obvious changes.Conclusions In the present study, the decrease of P53 gene expression at cellular level is achieved, however, the liver P53 protein in the marmoset liver is not significantly changes.Further optimization of the way of infection is needed in the future.

Objective To compare the efficiency of intra-articular injection of tranexamic acid (TXA) and autolo-gous transfusion drain on the blood loss after total knee arthroplasty (TKA). Methods A total of 124 patients (124 knees) with varus knee osteoarthritis, who were performed TKA,were retrospectively analyzed. Patients included 24 males and 100 females. The mean age was(65.03±6.84)years. Due to the blood loss control method, patients were divided into two groups including TXA application group (test group, n=49) and autologous transfusion drain group (control group, n=75). The data of blood routine examination, blood loss and blood transfusion after TKA were analyzed. Results The blood transfusion rates were 10.20%(5/49) in test group and 17.33%(13/75) in control group 7 days after TKA surgery. There was no signifi-cant difference between two groups (P>0.05). There were significant differences in red blood cell (RBC), hemoglobin (Hb) and haematocrit (HCT) between groups and effects of interaction in the two groups (P＜0.01). There were significantly higher values of RBC, Hb and HCT at 1, 3 and 7 days after surgery in test group than those of control group (P＜0.05).The total blood loss 1 and 3 days after TKA was significantly lower in test group than that of control group (P＜0.05). There was no sig-nificant difference in the blood loss 7 days after surgery between two groups (P>0.05). Conclusion The single dose intra-articular injection of tranexamic acid is a safe and effective procedure for hemostasis after TKA.

Objective In order to establish a rhesus monkey model of p53 gene silencing, firstly we screened and determined the effective silencing targets of p53 gene at the cellular level in rhesus monkey.Methods The expression of p53 gene was detected in COS-7 cells ( derived from the kidney of the African Green Monkey, Cercopithecus aethiops).Three small hairpin RNA ( shRNA) sequences targeting rhesus monkey p53 gene were designed, analysed by bioinformatics, and inserted into lentivirus-based gene silencing constructs FUGW-TDT.The plasmids of p53-RNAi and control vector were transfected into the COS-7 cells, respectively.The suppression of p53 mRNA was detected by real-time PCR, and the changes of p53 protein expression were detected by Western blot assay.Results p53 gene expression was detected in COS-7 cells.Bioinformatics analysis showed that three gene-silencing sequences were screened which lied in the open reading frame ( ORF) region and targeted 238 -258bp, 681 -701bp, 169 -189bp of the rhesus monkey p53 mRNA.At 48 hrs after transfection of the three silencing constructs, p53 mRNA was suppressed by(87.17 ±4.03)%, ( 72.62 ±4.11)% and(76.22 ±0.98 )%, and p53 protein was suppressed by ( 84.44 ±2.18 )%, ( 71.04 ±1.18)% and ( 74.17 ±0.95 )%, respectively. Conclusions We obtained three effective target sequences showing high efficiency in p53silencing, which can be used in further studies on gene silencing in rhesus monkey.