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The assay was used in HIV/AIDS surveillance sentinel sites to identify recent HIV-1 infection, to estimate HIV-1 incidence and understand the epidemic trends among men who have sex with men during 2011-2015. During 2011-2015, the HIV-1 incidence of men who have sex with men was 5.16%(95 %CI : 4.65%-5.66%) in Sichuan Province. According to, a total of 9 cities had been divided into two type of regions: the first type(the proportion of live HIV/AIDS accounts for more than 0.1% of the permanent population, and the number of live HIV/AIDS has reached 500 cases and above) and the second type(the proportion of live HIV/AIDS accounts for 0.03% to 0.100% of the permanent population, and the number of live HIV/AIDS has reached 100-500 cases). During 2011-2015, the HIV-1 incidence of the second type was 4.24% (95 %CI : 3.72%-4.76%). The HIV-1 incidence of men who have sex with men was at a high level. The spread of HIV-1 to the second region was possible.

Objective: Data from the HIV/AIDS surveillance sentinel sites was used to identify the recent HIV-1 infections and to estimate the HIV-1 incidence and epidemic trends among intravenous drug users (IDU), MSM, female sex workers and men attending the sexually transmitted disease clinics in Sichuan province. Methods: Specimens collected from IDUs, MSM, female sex workers and men attending the sexually transmitted disease clinics sentinel sites were confirmed as HIV-1 positive and tested with BED-CEIA. Annual HIV-1 prevalence and incidence rates were calculated and the incidence was adjusted by McNermar method. Results: A total number of 194 223 serum specimens were collected and HIV antibody tested, with 5 297 HIV-1 positive. 4 640 of the positives underwent BED-CEIA, with 749 identified as recent infections. During 2011-2015, HIV-1 incidence rates of the four types of population appeared as 5.16% (95% CI : 4.65-5.66), 0.22% (95% CI :0.16-0.28), 0.57%(95% CI : 0.45-0.69), 7.53% (95% CI : 6.06-9.01) and 0.44% (95% CI : 0.36-0.53) respectively. Significant differences were seen in the HIV-1 incidence rates. Conclusions: The HIV-1 incidence rates of IDUs from other sentinel sites in Sichuan province, female sex workers and men attending the sexually transmitted disease clinics appeared low, showing that the AIDS prevention and control activities worked effectively. However, the HIV-1 incidence of MSM was still at high level and even rising, suggesting that HIV-1 transmission between MSM and IDUs was possible.

In this study, we optimized a restriction-ligation-free (RLF) method to save time and cost of constructing multiple plasmids with the same gene insert, and examined the efficacy of RLF on high-throughput multi-plasmid cloning. This method utilizes the precise DNA repair and recombination systems within Escherichia coli, which allows to bypass the in vitro restriction and ligation enzyme reactions commonly included in routine cloning procedures. A homologous arm is linked to the 5'-end of the forward primer used to amplify both the target gene and vector. A different homologous arm is linked to the 5'-end of the reverse primer. Therefore, genes can be cloned into the vectors by homologous recombination after co-transformation of the amplified target gene and the linearized vector, which bear the same homologous arm on either end. More than twenty-four different plasmids were generated by this method, which uses two simple polymerase chain reaction steps. This method is highly efficient in cloning any gene of interest into any vector at any site without sequence constraints, as no restriction and ligation reactions are required.

Quantitative structure-activity relationships (QSARs) based on the octanol/water partition coefficient were employed to predict acute toxicities of 36 substituted aromatic compounds and their mixtures. In this study, the model developed by Verhaar et al. was modified and used to calculate octano/water partition coefficients of chemical mixtures. To validate the model, acute toxicities of these chemicals were measured to Vibrio fischeri in terms of EC50. The results indicated that the obtained QSAR models could be used to predict toxicities of samples consi sting of these substituted aromatic compounds, individually or in combinations. The obtained equations were proved to be robust enough by using the leave-one-out test method. By classifying these chemicals into two groups, polar and non-polar, the toxicities of chemical mixtures within each group can be predicted accurately from their calculated partition coefficients.

Halogenated aromatic compounds exist widely in soil and aqueous environment. The study of their transport and distribution is quite important for pollution control and risk assessment. In the present work the adsorption coefficients of 28 halogenated benzenes, anilines and phenols on yellow-brown soil were measured with batch equilibrium method, and a prediction model was developed through the quantitative structure-property relationship (QSPR) technique. Then the obtained model was tested with Monte Carlo simulation and Jacknife methods. The results indicated that it was robust enough to estimate soil adsorption behaviors for the tested compounds. Based on the obtained model it could be deduced that the adsorption of halogenated aromatics on yellow-brown soil was not a simple partitioning process but involved complicated interactions.

A new quantitative structure-activity relationship (QSAR) technique combining the Free-Wilson method and constructed quantum chemical parameters was used to simulate the aqueous solubility (Sw), 1-octanol/water partition coefficient (Kow) of 14 new synthesized benzanilide derivatives and their 96 h acute toxicity (EC50) to Daphnia magna. The mode of action of the 14 selected compounds to Daphnia magna was shown to be a complex process involving a physical partition stage and a bio-chemical reaction stage. The results also indicated that the joint (QSAR) analysis was much effective than the original Free-Wilson method and Hansch method not only in predicting properties/toxicity, but also in investigating the mode of action of chemicals.