[Adsorption Mechanism for Phosphate in Aqueous Solutions of Calcium/Aluminum-rich Sludge Biochar Composite].

Excess sludge is rich in organic matter but also contains heavy metals, pathogens, and harmful substances. In this study, hydroaluminite and excess sludge were used as raw materials to reduce the risk of heavy metals leaching from sludge by coagulation and co-pyrolysis, and its phosphate adsorption characteristics were studied. The results showed that the leaching amount of Zn, Cu, Cd, and Ni in sludge biochar decreased with the increase in the hydroaluminite dosage. The sludge biochar composite (1:1HB800), prepared by co-pyrolysis of hydroaluminite and excess sludge with a mass ratio of 1:1 as well as rich in calcium and aluminum, had lowest leaching risk of heavy metals and showed the high adsorption capacity for phosphate. The process could be fitted by the Langmuir adsorption isotherm (R2=0.93), and the maximum phosphate adsorption capacity at 25℃ was 51.38 mg·g-1. The pseudo second-order kinetic model could well describe the adsorption process of 1:1HB800 for high concentration phosphate, and its adsorption rate was controlled by both surface adsorption and particle diffusion. Compared with that in the neutral solution, 1:1HB800 had better phosphate capacity in the acidic and alkaline aqueous solutions, which was related to the leaching amount of calcium/aluminum in 1:1HB800 and the existence form of aluminum under the different pH conditions. FTIR, XRD, SEM, zero potential point, and Ca2+/Al3+ leaching experiments indicated that the main adsorption mechanisms for phosphate by 1:1HB800 were co-precipitation (interaction between Ca2+/Al3+ and phosphate), ligand exchange (hydroxyl), and electrostatic interaction. Therefore, 1:1HB800 can provide a feasible alternative for the removal of phosphate in aqueous solutions and also provide a potential new method for the resource utilization and harmless treatment of excess sludge.

Establishment of an innovative and sustainable PCR technique for 1534 locus mutation of the knockdown resistance (kdr) gene in the dengue vector Aedes albopictus.

BACKGROUND: Mutation of the voltage-gated sodium channel (VGSC) gene, or knockdown resistance (kdr) gene, is an important resistance mechanism against DDT and pyrethroids for dengue vector Aedes albopictus. A phenylalanine to serine (F1534S), leucine (F1534L) and cysteine (F1534C) substitution were detected in many Ae. albopictus populations around the world, and the mutant allele frequencies have been increasing in recent years. Therefore, it is essential to establish a simple, time-saving and cost-effective procedure to monitor the alleles in large-scale studies. METHODS: Based on the mutation genotypes of the 1534 locus in the kdr gene, F/F, F/S, F/C, F/L, S/S, C/C, L/L and S/C, we designed specific forward and reverse primers and optimized the reaction conditions for establishing of the allele-specific PCR(AS-PCR) detection technique. DNA sequencing in this study was taken as the gold standard, and used to determine the accuracy of AS-PCR. RESULTS: The designed AS-PCR technique showed high specificity for distinguishing the mutations at the 1534 locus, as the accuracy for F/F, F/S, F/C, F/L, S/S, C/C and S/C were 100%, 95.35%, 100%, 100%, 100%, 100% and 100%, respectively. CONCLUSIONS: The designed AS-PCR technique effectively distinguished individual genotypes for the mutations at the 1534 locus in the kdr gene, which could facilitate the knockdown resistance surveillance in Ae. albopictus in large-scale studies.

Screening, verification, and analysis of biomarkers for drug-induced cardiac toxicity in vitro based on RTCA coupled with PCR Array technology.

Cardiotoxicity is one of the most serious side effects of new drugs. Early detection of the drug induced cardiotoxicity based on the biomarkers provides an important preventative strategy for detecting potential cardiotoxicity of candidate drugs. In this study, we aim to identify the predictive genomics biomarkers for drug-induced cardiac toxicity based on the RTCA coupled with PCR Array technology in primary cells. Three prototypical cardiotoxic compounds (doxorubicin, isoproterenol, ouabain) with different mechanisms were firstly real-time monitored to diagnose the cytotoxicity by using the RTCA, while the functional alterations of cardiomyocytes were also monitored by analyzing the beating frequency of cardiomyocytes. Then cardiac specific toxicity gene expression changes were studied by using the technology of PCR Array, which can detect the changes of 84 cardiac functions related genes. Rps6kb1 was identified to be the common cardiac biomarkers by using multivariate statistical and integration analyses. The biomarker was further verified by selecting other drugs with or without cardiotoxicity, and the results showed that the gene exhibited specific changes in cardiac toxicity. Moreover, IPA was applied to combine relevant pathways of Rps6kb1, and identify the main types of cardiac toxicity. These results would further enrich the evaluating strategy of drug-induced cardiotoxicity in vitro, and Rps6kb1 could be used as the specific biomarker of cardiotoxcity during safety assessment of the novel drug candidates.

[Interaction between ATM and radiation-activated phosphorylation of P53 and P21].

BACKGROUND & OBJECTIVE: ATM gene is a member of PI-3K kinase family. ATM protein is capable of controlling DNA repair process and cell cycle checkpoint. In AT cells from ataxia-telangiectasia (AT) patients, ATM gene mutation leads to the deficiency of ionizing radiation-activated phosphorylation of P53 and P21. It shows ATM gene could mediate the phosphorylation of P53 and P21. This study was to explore the interaction between ATM and P53, and to observe whether ATM directly medicates the phosphorylation of P21 in a P53-independent way. METHODS: pEBS7-YZ5 vector containing ATM cDNA was transfected into AT cells by electroperforation. The cells expressing ATM protein stably were screened with hygromycin, and identified by reverse transcription-polymerase chain reaction (RT-PCR). The interaction between ATM and P53 in pEBS7-YZ5-AT cells was assessed by co-immunoprecipitation and Western blot. K562 cells served as a P53 mutation cell model to study whether ATM could interact with the phosphorylation of P21. RESULTS: pEBS7-YZ5 was transfected into AT cells successfully. RT-PCR detected fragment of ATM cDNA. After exposed to ionizing radiation, P53 of pEBS7-YZ5-AT cells was phosphorylated, and immunoprecipitation showed interaction between ATM and P53; P21 of K562 cells was phosphorylated, P21 protein was detected in the immunoprecipitation of ATM antibody-complex. CONCLUSION: Ionizing radiation-activated ATM kinase could interact with the phosphorylation of P53 and P21 in both P53 wild type and mutant type cells.