Objective To establish a multiplex real-time quantitative polymerase chain reaction (MRQPCR) assay for fast and simultaneous detection of Escherichia coli (E.coli) and Candida albicans (C.albicans) genes in human whole blood,in order to facilitate differentiation of the types of microorganism and evaluation of the severity of bacterial or fungi translocation due to impaired gut barrier,hence providing help to select specific antimicrobial agents.Methods The β-D-galactosidase gene of E.coli and ITS2 gene of C.albicans were selected as the target genes for designing primers and probes.E.coli and C.albicans genomes were extracted with QIAamp(R) DNA Blood Mini Kit,and the 25 μl TaqMan MRQ-PCR amplification reaction system was established.18 simulated human whole blood samples and 10 whole blood samples from febrile surgical patients were detected for E.coli and C.albicans genes using MRQ-PCR.Results The specificity of the primers and probes were excellent.The correlation coefficients of the standard curves of E.coli and C.albicans were 0.994-0.999 and 0.994-0.998,respectively;and the efficiency of amplification were 0.894-1.022 and 0.905-1.028,respectively.In the standard samples,the lowest detection limits of E.coli and C.albicans were 13.9 copies/μl and 0.8 cfu/μl,respectively;the sensitivity was 100％ and 99.69％,the specificity was 100％ and 94.73％,respectively;the average recovery rates were (101.89 ± 5.69)％ and (103.74 ± 4.64)％ respectively;the intra-batch coefficients of variance (CV) in detecting the genes were (13.14 ± 10.27)％ and (19.18 ± 8.54)％,respectively,and the inter-batch CV were (14.35 ± 9.34)％ and (18.31 ± 10.25) ％,respectively.In human whole blood,the lowest detection limits of E.coli and C.albicans were 12 455.2 copies/ml and 800.3 cfu/ml,respectively;the average recovery rates were (111.60 ± 11.06) ％ and (99.96 ± 6.16) ％,respectively;the intra-batch CV in detecting the genes were (11.02 ± 5.65) ％ and (8.14 ± 7.29)％,respectively,and the average inter-batch CV were (12.88 ± 7.59)％ and (18.62 ± 9.14)％.Conclusions MRQ-PCR is a rapid,sensitive,specific,accurate,and reproducible method for simultaneous detection of E.coli and C.albicans genes in human whole blood,with sample-,cost-,and time-saving advantages.It is a promising technique for rapid differentiation between fungi and bacteria,which could help targeted administration and evaluation of antimicrobial agents,and help to assess the consequence of gut barrier damage and the efficacy of treatment.

BACKGROUND: BALB/c and C57BL/6 mice are two inbred strains, but after voluntary movement, there is no report on how to scientifical y reasonably select behavioral experiment methods and indicators and to evaluate the learning and memory abilities of mice.
OBJECTIVE: To analyze and compare the behavioral indicators between BALB/c and C57BL/6 mice fol owing voluntary wheel running, to explore the effect of exercise on learning and memory, and to provide a reference for selecting reasonable behavioral indicators.
METHODS: 2.5-month-old BALB/c and C57BL/6 mice were randomly divided into control and voluntary wheel running groups. Independent running wheel movement of mice was recorded with VitalView system. 4 weeks later, newborn neurons were labeled via DCX immunofluorescence. Spatial learning, memory and exploration abilities were compared through new arm test, new object recognition test and Morris water maze test.
RESULTS AND CONCLUSION: (1) The mean spontaneous activity of BALB/c mice daily was 2.56 fold of that of C57BL/6 mice during wheel running (P < 0.001). (2) Hippocampal DCX-positive cel s in exercised BALB/c and C57BL/6 mice were more than those in control group. (3) Meantime, exhibited by higher frequencies to explore new arm or object, and longer time and distance of moving around them, the learning and exploring capability was improved after exercising (P < 0.001), especial y in BALB/c mice. (4) Wheel running C57BL/6 mice exhibited progressed spatial learning and memory abilities compared with control mice in Morris water maze test, characterized by decreased latency to target, elevated target crossings and longer time or distance in quadrant zone (P < 0.05). However, there was no significant difference between wheel running and control BALB/c mice. Taken these data together, voluntary wheel running contributed to hippocampal neurogenesis of BALB/c and C57BL/6 mice, accompanied by the change of learning and memory capability, which could be detected properly via both new arm test and new object recognition test, but for Morris water maze test, C57BL/6 mice might be superior to BALB/c mice.

Objective To establish a rapid real-time quantitative polymerase chain reaction (RQ-PCR)assay in quantifying and detecting Staphylococcus aureus DNA from human venous blood samples,so as to quantificationally evaluate the systemic infection caused or deteriorated by intestinal bacteria translocation.Methods Totally 26 clinical blood samples and 15 simulation blood samples were detected.The primers and TaqMan probe were designed targeting the highly conserved house-keeping femA gene of Staphylococcus aureus,and a 20 μl RQ-PCR amplification reaction system was established.The standard curve was built based on the recombinant plasmid DNA containing the amplicon of the target gene,and genomic DNA was extracted using QIAamp DNA Blood Mini Kit.Results The specificity of primers and probe was excellent,the detecting limit was 100 copies/μl (103 CFU/ml),the sensitivity was 99.7％,and the specificity was 94.6％.The correlation coefficient of the standard curve was between 0.9918 and 0.9997.For samples with different Staphylococcus anreus concentrations,the average accuracy of the RQ-PCR assay was (96.25 ± 2.26) ％ ; the intra-and interassay coefficients of variation were (8.06 ±0.07)％ and (10.01 ±4.40)％,respectively.The average recovery rate of Staphylococcus aureus DNA in blood samples was (111.72 ± 20.72) ％.In clinical blood samples,the positive rate of Staphylococcus aureus DNA was 15.4％ (4/26),while the blood culture of these samples all produced negative result for Staphylococcus aureus.Conclusion RQ-PCR assays is a rapid,sensitive,and specific method with good repetitiveness and can be used in the quantitative detection of Staphylococcus aureus in whole blood samples.

Objective:To assess the clinical effects of carbon fiber reinforcement on the“All-on-Four”provisional prostheses.Methods:Provisional prostheses were divided into control group and carbon fiber reinforcing group according to whether carbon fiber reinforcement was used in the provisional prostheses base resin.In our study,a total of 60 patients (32 males and 28 females)with 71 provisional prostheses (28 maxilla and 43 mandible)were enrolled between April 2008 and December 201 2 for control group;a total of 23 patients (1 3 males and 1 0 females)with 28 provisional prostheses (9 maxillas and 1 9 mandi-bles)were enrolled between January 201 3 and March 201 4 for carbon fiber reinforcing group.The infor-mation of provisional prostheses in the patients was recorded according to preoperative examination.We used the date of definitive prosthesis restoration as the cut-off point,observing whether fracture occurred on the provisional prostheses in the two groups.Additionally we observed whether fiber exposure occurred on the tissue surface of the provisional prostheses and caused mucosal irritation.The interface between the denture base resin and the fibers was examined using scanning electron microscopy (SEM).Results:The age [(57.3 ±1 0.1 )years vs.(55.1 ±1 1 .4)years],gender (32 males and 28 females vs.1 3 males and 1 0 females),maxilla and mandible distributions (28 maxillas and 43 mandibles vs.9 maxillas and 1 9 mandibles),the number of extraction jaws (46 vs.23 ),the average using time [(7 .8 ±1 .3 ) months vs.(7 .5 ±1 .1 )months],and the opposing dentition distributions of provisional prostheses of the patients showed no significant differences between the control and reinforcing groups.There were 21 (29 .6%)fractures that occurred on the 71 provisional prostheses in the control group;there was no frac-ture that occurred on the 28 provisional prosthesesin the carbon fiber reinforcing group.The fracture rate of the carbon fiber reinforcing group was significantly lower than that of the control group (P=0.001 ). No carbon fiber exposure and mucosal irritation were observed from clinical examination.SEM revealed relatively continuous contact between the fiber and acrylic resin,and the resin particles adhered on the surface of the carbon fibers.Conclusion:The addition of carbon fibers between abutments placed on“All-on-Four”provisional fixed denture base resin may be clinically effective in preventing “All-on-Four”denture fracture and can provide several advantages for clinical use.

Objective To establish a real-time quantitative polymerase chain reaction (RQ-PCR) assay for fast detection of Aspergillus fumigatus genome in human whole blood samples and explore its clinical application.Methods The primers and the TaqMan-probe were designed on the basis of the multi-copy ITS1-5. 8S region of the rDNA of Aspergillus fumigatus. The Aspergillus fumigatus genomic DNA were extracted with QIAamp(R) DNA Blood Mini Kit.A 20 μl RQ-PCR amplification system was established, and the simulated blood samples containing various given load of Aspergillus fumigatus genome and the 66 whole blood samples of the surgical febrile patients were examined. Results The detection limit of the RQ-PCR instrument is 10-1 genomes/μl DNA sample,namely 78 CFU/ml whole blood. The specificity and the sensitivity were 94. 25% and 99. 04% respectively; and the positive predictive value and negative predictive value were 97. 63% and 97. 62% respectively. The average relative error of the quantitative results was (3. 67 ±13. 19)%, and the intra- and the inter-assay average coefficients of variation were (12.38 ± 1. 53)% and (16. 27 ±2. 72)% , respectively. The average recovery rate of Aspergillus fumigatus genomic DNA in human whole blood samples was (107. 81 ±25. 92)% , and the average coefficient of variation of the average recovery rate was (26. 24 ± 5.62) % . No Aspergillus fumigatus genomic DNA was detected among the 66 blood samples of the surgical febrile patients. Conclusions The RQ-PCR assay for fast quantitative detection of Aspergillus fumigatus genome in human whole blood samples is of high sensitivity, specificity,accuracy and precision. The Aspergillus fumigatus genome was not detected in this group of surgical febrile patients.

Objective To establish the real-time quantitative PCR (RQ-PCR) assay for detecting Candida albicans (C.albicans) in whole blood and its clinical application in the febrile surgical patients who may develop gut barrier damage and gut microorganism translocation.Methods The NAG1 gene,which is a single copy in C.albicans genome,was selected as the target gene for designing the primers and probe.The plasmid was fabricated and produced as standard samples.C.albicans genomes were extracted with QIAamp(R) DNA Blood Mini Kit,and the total 20 μl TaqMan RQ-PCR amplification reaction system was established.The 74 venous blood samples from the surgical febrile patients were detected for C.albicans load.Results The specificities of the primers and probe were excellent,the correlation coefficients of the standard curves were between 0.9918 and 0.9985,and the efficiency of amplification was 0.88-1.027 for the samples above the lowest detection limit (100 copies/μl examine fluid,or nearly 1.1 × 103 cfu/ml whole blood).The average accuracy of the RQ-PCR equipment was (99.64±2.08) %,the sensitivity was 97.46%,the specificity was 100%,and the average coefficients of variation (CV) of the intra-and inter-assay were (14.76±2.64)% and (17.85±3.53)%,respectively.The average recovery rate of C.albicans DNA in whole blood samples was (88.60±5.73) %,and the average CV of recovery rate was (11.70 ±5.36) %.The number of copies of C.albicans genes per unit blood was not significantly different among the same original blood samples stored separately under-20℃ for 3 or 6 months when compared with its freshly collected blood (P = 0.267).In the 74 whole blood samples obtained from the febrile surgical patients,the positive rate of C.albicans genes was 2.7% and the highest load was 4.42×103 cfu/ml.Conclusions RQ-PCR is a rapid,sensitive,highly specific,and reproducible method in detecting C.albicans NAG1 gene.Clinically it can be used to quantitatively evaluate the numbers of C.albicans in the whole blood.A small percentage of the febrile surgical patients may develop blood infection of C.albicans.

ObjectiveTo isolate and study the biological characteristics of severe acute respiratory syndrome coronavirus 2 （SARS-CoV-2） from feces of coronavirus disease 2019 （COVID-19） patients. MethodsVero E6 cells were used for virus isolation and the isolated strains were tested by nucleic acid test， immunofluorescence test， virulence test and whole genome sequencing. 50% tissue culture infective dose （TCID₅₀） was calculated after the cell cultures of each generation were collected ResultsEight fecal specimens were inoculated with Vero E6 cells after treatment and cultured for 48 h. One specimen showed obvious cytopathic effect on Vero E6 cells. One SARS-CoV-2 out of 8 fecal samples from COVID-19 patients were isolated， and separation rate was 12.5%. The TCID₅₀ of P1， P2 and P3 were 10^4.0/0.2 mL， 10^4.5/0.2 mL and 10^4.75/0.2 mL， respectively. Only one of the 8 stool samples had SARS-CoV-2 virus replication and amplification， and the Ct value of the nucleic acid detection was about 10. The sequence of the isolation was more than 99.99% homologous with that of Wuhan-Hu-1（GenBank MN908947）. ConclusionThe SARS-CoV-2 strain is isolated from the fecal samples of COVID-19 cases and is confirmed by genomic sequencing and immunofluorescence test， which indicates the presence of live virus in feces of COVID-19 cases.

OBJECTIVE: To develop a radioactive sewage purification device that can effectively filter the nuclides in low-level nuclide-contaminated wastewater. METHODS: The radioactive sewage purification device was composed of lifting pump, stack filter, multi-medium filter, security filter, tubular ultrafiltration membrane, high-pressure pump and reverse osmotic membrane. The combined process of adsorption-ultrafiltration-reverse osmosis was used to separate radioactive elements from wastewater by reverse osmosis membrane separation system. Through two-stage multi-medium filter circulation system circulation treatment, radioactive sewage was purified. The flow rate of water treatment is 20 L/min. The filtration efficiency and purification efficiency of the device were tested by filtration experiments on elements containing radionuclide and purification experiments on radionuclide.RESULTS: The filtration efficiency on iodine, potassium, strontium and cesium, that are the common elements in radioactive sewage samples were 97.88%, 98.38%, 99.99% and 99.80%, respectively. The single purification efficiency of radionuclide ~(40)K in low-level radioactive sewage was over 90.00%. CONCLUSION: The device has high filtering efficiency for common elements such as iodine, potassium, strontium and cesium in sewage and high removal rate of radioactive activity for sewage containing ~(40)K. It can be further optimized and transformed into a suitable radioactive sewage water purifier.