A 5-year molecular epidemiology survey of human enterovirus 71 before vaccine application in Yunnan Province, China.

Enterovirus A71 (EV-A71) infection is known to cause hand, foot, and mouth disease (HFMD). Last year, an inactivated EV-A71 whole virus vaccine was used to prevent this disease in Yunnan, China. To obtain a viral genetic background for evaluating vaccine protection and monitor the adaptive evolution of the virus after the vaccination, a 5-year molecular epidemiology survey was performed before the vaccination. Twenty-six EV-A71 strains were separated from 561 stool specimens of patients with serious HFMD. The whole-genomic sequences of these strains were sequenced. Phylogenetic trees were constructed, and the mutation spectra were analyzed based on these viral sequences. There was no obvious mutation for the circular EV-A71 strains of the same year. Pathogenic EV-A71 strains may arise from a "subgroup" randomly each year. Whole-genomic analyses showed that a hotspot nonsynonymous substitution potentially affecting the immunogenicity of vaccines was found in the 2A gene, but not in genes of the viral capsid proteins, and the genetic diversity of whole viral genomes associated with the incidence of HFMD. Therefore, it will be valuable to monitor the genome-wide changes of EV-A71 to detect the adaptive mutations affecting immunogenicity or perform investigations using genetic diversity as a parameter.

[Permeation mechanism of phenolic acid components from traditional Chinese medicine on PES membrane separation process].

To explore the permeation mechanism of micro-molecule medicinal ingredients of water extract of tradition Chinese medicine(TCM) in membrane separation process. With phenolic acid components as the model solute, five phenolic acids with similar molecular weight and structure, namely gallic acid, protocatechuate acid, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid and salicylic acid, were selected in the PES membrane separation experiments. With the relative flux and the transmission rate as indexes, the scanning electron microscopy(SEM) and the electrochemical impedance spectroscopy(EIS) were used to analyze the permeation mechanism of different phenolic acid components. The results showed phenolic acids with similar molecular weight had different permeation behaviors, with decreased relative flux and increased solute permeation with the increase of solute concentration. According to the permeation behavior analyzed by the molecular structure of solute, the transmission rate of phenolic acids increased with the increase of the number of hydroxyl, and the order of substituent positions of phenolic acids based on the permeation rate as follows: para-substituted > meta-substitution > ortho-substitution. Electrochemical impedance spectroscopy reflected the role of charge repulsion in the membrane process; that is to say, the greater the resistance is, the less the solute permeation is. Therefore, the permeation phenomenon of the phenolic acid components in the PES membrane is not only the result of simple sieving mechanisms, but also has the effects of steric hindrance and charge repulsion during the membrane process.

[Comparative study on four membrane modules in membrane filtration process of Huanglian Jiedu decoction].

OBJECTIVE: To compare the membrane filtration process of four membrane modules namely, FMX rotating disk flat membrane module, hollow fiber membrane module, tubular membrane module and filter cup membrane module, with traditional Chinese medicine compound Huanglian Jiedu decoction as the experimental subject. METHOD: Under the same experimental operating conditions, the four membrane modules in membrane filtration process of Huanglian Jiedu decoction were compared in terms flux, resistance distribution, transmittance of index components and membrane fouling. RESULT AND CONCLUSION: Three membrane modules in the dynamic filtration form--FMX rotating disk flat membrane module, hollow fiber membrane module and tubular membrane module had more advantages than filter cup membrane module in the static dead-end filtration form in terms of permeate flux, transmittance of index components and membrane fouling. However, FMX membrane module that made the fluid in a strong vortex status had better performance than hollow fiber membrane and tubular membrane module in permeate flux and membrane fouling.

Different EDC/NHS activation mechanisms between PAA and PMAA brushes and the following amidation reactions.

Infrared spectroscopy was applied to investigate the well-known EDC/NHS (N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide/N-hydroxysuccinimide) activation details of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) brushes grafted on porous silicon. Succinimidyl ester (NHS-ester) is generally believed to be the dominant intermediate product, conveniently used to immobilize biomolecules containing free primary amino groups via amide linkage. To our surprise, the infrared spectral details revealed that the EDC/NHS activation of PMAA generated anhydride (estimated at around 76% yield and 70% composition), but not NHS-ester (around 5% yield and 11% composition) under the well-documented reaction conditions, as the predominant intermediate product. In contrast, EDC/NHS activation of PAA still follows the general rule, i.e., the expected NHS-ester is the dominant intermediate product (around 45% yield and 57% composition), anhydride the side product (40% yield and 28% composition), under the optimum reaction conditions. The following amidation on PAA-based NHS-esters with a model amine-containing compound, L-leucine methyl ester, generated approximately 70% amides and 30% carboxylates. In contrast, amidation of PAA- or PMAA-based anhydrides with L-leucine methyl ester only produced less than 30% amides but more than 70% carboxylates. The above reaction yields and percentage compositions were estimated by fitting the carbonyl stretching region with 5 possible species, NHS-ester, anhydride, N-acylurea, unreacted acid, unhydrolyzed tert-butyl ester, and using the Beer-Lambert law. The different surface chemistry mechanisms will bring significant effects on the performance of surface chemistry-derived devices such as biochips, biosensors, and biomaterials.

AFM and multiple transmission-reflection infrared spectroscopy (MTR-IR) studies on formation of air-stable supported lipid bilayers.

Supported lipid bilayers (SLBs) were prepared by deposition of unilamellar vesicles on a silicon substrate. Atomic force microscopy (AFM) and a new Multiple Transmission-Reflection Infrared Spectroscopy (MTR-IR) developed by us were used to trace the dynamic formation of lipid bilayers on the silicon surfaces. The evolution from deformation of vesicles to formation of bilayers can be distinguished clearly by AFM imaging. MTR-IR provided high quality infrared spectra of ultrathin lipid bilayers with high sensitivity and high signal to noise ratio (SNR). The structural and orientational changes during vesicle's fusion were monitored with MTR-IR. MTR-IR shows superiority over other infrared approaches for ultrathin films on standard silicon wafers in view of its economy and high sensitivity. Both MTR-IR and AFM results were consistent with each other and they provided more information for understanding the self-assembling procedure of SLBs.

[Formation Mechanism of Self-forming Dynamic Membrane During Separation of High-concentration Sewage Sludge Fermented for Acid Production].

Self-forming dynamic membrane was used to separate high-concentration sludge fermentation liquid, and the formation mechanism and separation efficiency of dynamic membrane were investigated. The results indicated that the impact of sludge concentrations was negligible on the formation of dynamic membrane. Though membrane flux could be influenced by sludge concentration at the initial stage of membrane formation process, the influence was not obvious at the stable stage. Membrane flux was improved with increasing filter cloth pore size and stirring speeds. Moreover, the results indicated that the formation process of dynamic membrane followed the dead-end filtration model, which could be divided into four stages. Firstly, filter cloth pore was blocked by those sludge particles with the diameter similar to the pore size of filter cloth. Secondly, sludge particles formed monolayer sludge on the filter cloth. Thirdly, sludge particles formed multilayer sludge on the filter cloth. Finally, large sludge particles deposited onto the sludge layer. After formation of the dynamic membrane, the retention efficiency of sludge particles and SCOD could reach 98% and 28% , respectively, and the permeation efficiency of VFAs was over 82%. Proteins in EPS were the main component of the dynamic membrane.

Facile one-step coating approach to magnetic submicron particles with poly(ethylene glycol) coats and abundant accessible carboxyl groups.

PURPOSE: Magnetic submicron particles (MSPs) are pivotal biomaterials for magnetic separations in bioanalyses, but their preparation remains a technical challenge. In this report, a facile one-step coating approach to MSPs suitable for magnetic separations was investigated. METHODS: Polyethylene glycol) (PEG) was derived into PEG-bis-(maleic monoester) and maleic monoester-PEG-succinic monoester as the monomers. Magnetofluids were prepared via chemical co-precipitation and dispersion with the monomers. MSPs were prepared via one-step coating of magnetofluids in a water-in-oil microemulsion system of aerosol-OT and heptane by radical co-polymerization of such monomers. RESULTS: The resulting MSPs contained abundant carboxyl groups, exhibited negligible nonspecific adsorption of common substances and excellent suspension stability, appeared as irregular particles by electronic microscopy, and had submicron sizes of broad distribution by laser scattering. Saturation magnetizations and average particle sizes were affected mainly by the quantities of monomers used for coating magnetofluids, and steric hindrance around carboxyl groups was alleviated by the use of longer monomers of one polymerizable bond for coating. After optimizations, MSPs bearing saturation magnetizations over 46 emu/g, average sizes of 0.32 µm, and titrated carboxyl groups of about 0.21 mmol/g were obtained. After the activation of carboxyl groups on MSPs into N-hydroxysuccinimide ester, biotin was immobilized on MSPs and the resulting biotin-functionalized MSPs isolated the conjugate of streptavidin and alkaline phosphatase at about 2.1 mg/g MSPs; streptavidin was immobilized at about 10 mg/g MSPs and retained 81% ± 18% (n = 5) of the specific activity of the free form. CONCLUSION: The facile approach effectively prepares MSPs for magnetic separations.

[Analysis of possible factors that impact parents to accept dental general anesthesia].

PURPOSE: To analyze the possible factors that impact parents to accept dental general anesthesia (DGA) in pediatric dentistry, thus provide some reference when a pediatric dentist suggests DGA technique to parents in clinical practice. METHODS: DGA technique was explained to 299 surveyed subjects (mother or father), and then the questionnaires were filled in. Parental acceptance rate was determined by a 100mm visual analogue scale (VAS). At the left end of the line appeared the words "completely acceptable" (0mm); at the right end of the line appeared the words "completely unacceptable" (100mm). Each parent placed a mark on the horizontal line at a point corresponding to their personal acceptance rating of the DGA technique. The acceptance rating of DGA was determined by measuring the distance on VAS line from the left end to the marked point by the subject. All statistical analysis was performed using the SPSS 11.0 software package. Difference between parental acceptance rates of DGA was compared using X(2) test. The correlation between independent variables and the acceptance rate of DGA was analyzed using Spearman correlation test. The possible factors in this study were consisted of the age of the child, the frequency of dental visit for the child, the age of the parents, their educational level, monthly income and the evaluated score of the child cooperation degree. RESULTS: Spearman correlation analysis demonstrated that there was no correlation between the DGA acceptance rate and the age of the child, the age of the parents, educational level, and the frequency of dental visit for the child. For the surveyed mother, acceptance rate of DGA was positively related to the monthly income (r=0.21,P<0.05) and negatively related with the evaluated score of child cooperation degree( r=-0.137,P<0.05). CONCLUSIONS: There is no correlation between the DGA acceptance rate and the age of the child, age of the parents, educational level and the frequency of dental visit for the child. There is different considerations from mother and father when choosing DGA.The major factors for mother to accept DGA was the income level and the status of children's cooperation.Adequate explanation of DGA to both father and mother should be emphasized. At present family income may be the most important factor for the lower acceptance rate of DGA technique in China.

[Survey of parental acceptance rate to behavior management techniques used in pediatric dentistry].

PURPOSE: To investigate the parental acceptance rate to behavior management techniques (BMT) used in pediatric dentistry. METHODS: Two hundred and eighty-five subjects (mother or father) were included in this survey. Five behavior management techniques including (1)tell-show-do; (2)voice control; (3)passive restraint; (4)sedation; (5) general anesthesia commonly used in pediatric dentistry were explained to the parents and then filled the questionnaires by either of the parents, including the parental age, gender, educational level and income, The answerer rated their acceptance of each technique using a visual analogue scale (VAS), a continuous scale ranging from 0 to 100mm. The left end represented "completely acceptable" and the right end represented "completely unacceptable". The subjects were instructed to rate the acceptability of each technique by placing a mark on the VAS response line. The acceptability rating of each technique by the subject was determined by measuring the distance between VAS line from the left end to the mark. SPSS10.0 software was used for statistical analysis. VAS measurements were analyzed using a factorial analysis of variance (ANOVA). Student's t test was used to analyze the difference between the acceptance rates for different gender of the answerers. The correlation between independent variables consisted of parental gender, education level, income and behavior management techniques were analyzed using Spearman correlation test. RESULTS: The order of decreasing acceptance rate was as follows, tell-show-do, voice control, sedation, general anesthesia and passive restraint. The difference between each of them was statistically significant (F=215.2,P<0.01). The age and the education level of the parent did not have correlation with the acceptance rate of different BMTS. However, the income of the parents was relevant to the acceptance rate of general anesthesia by Spearman correlation analysis (P<0.01). The acceptance rate of tell-show-do and passive restraint were related to parental gender. According to Students's t test, female tended to accept tell-show-do more than males (P=0.011), nevertheless more males tended to accept passive restraint (P=0.001). CONCLUSION: No techniques were found to be totally acceptable by all parents. Adequate communication with parents is critical for acceptance of a behavior management technique. The selection of BMT needs informed consent of the parents.

[Relationship of caries experience between primary teeth and the first permanent molars in 100 children of 6-year-old].

OBJECTIVE: To investigate the correlation of caries experience between primary teeth and the first permanent molars. METHODS: A total of 100 school children 6 years old were surveyed. The caries diagnosis criteria defined by WHO were employed. The data were statistically analyzed by use of SAS. RESULTS: Fisher's exact test showed that there was association between the caries experience of primary teeth and that of the first permanent molars in 6-year-old children. The average dmft of primary teeth was in positive correlation with DMFT of the first permanent molars(r = 0.5629). The results were statistically significant. CONCLUSION: The primary tooth caries experience may play an important role in predicting permanent tooth caries. More attention was suggested to pay to the children with more primary teeth decayed.