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Post-transplant lymphoproliferative disorder (PTLD) is a lethal complication after pediatric liver transplantation, but information regarding risk factors for the development of PTLD remains unclear. This study was to identify characteristics and risk factors of PTLD.A total of 705 pediatric patients who underwent liver transplantation between January 2017 and October 2018 were studied. Impact of clinical characteristics and Epstein-Barr virus (EBV) infection on the development of PTLD was evaluated. In addition, ImmuKnow assay was adopted in partial patients to analyze the immune status.Twenty-five (3.5%) patients suffered from PLTD with a median time of 6 months (3-14 months) after transplantation. Extremely high tacrolimus (TAC) level was found in 2 fatal cases at PTLD onset. EBV infection was found in 468 (66.4%) patients. A higher peak EBV DNA loads (9590 copies/mL) within 3 months was a significant indicator for the onset of PTLD. In addition, the ImmuKnow assay demonstrated that overall immune response was significantly lower in patients with EBV infection and PTLD (P0.0001). The cumulative incidence of PTLD was also higher in patients with lower ATP value (≤187 ng/mL, P0.05).A careful monitoring of EBV DNA loads and tacrolimus concentration might be supportive in prevention of PTLD in pediatric patients after liver transplantation. In addition, application of the ImmuKnow assay may provide guidance in reducing immunosuppressive agents in treatment of PTLD.

In order to grind the ceramic blade surface with the Numerical Control contour evolution ultrasonic grinding method using the simple shape grinding wheel, primary comparative experiments of creep feed grinding with and without ultrasonic vibration were carried out to grind Al 2 O 3 ceramics so as to implore the effects of different process parameters on the machined surface quality. It can be concluded that when the direction of ultrasonic vibration is parallel to the direction of creep feed, the value of the surface roughness will be decreased; otherwise the surface quality will become worse. With the ultrasonic grinding method, the slower feed-rate, the smaller grinding depth, the higher grinding speed and the compound feed grinding method should be applied in order to improve the surface quality. The creep feed grinding mechanisms with and without ultrasonic vibration were analyzed theoretically from the experimental results. With the selected grinding parameters resulted from the experiments, the feasibility experiment of ultrasonic grinding ceramic blade surface was carried out.

The potential dechlorination of pentachlorophenol (PCP) in soil by a DCP-adapted consortium was investigated Results show that PCP dechlorination was enhanced under sulfate reduction and methanogenic conditions, but inhibited under denitrifying conditions within a 20-day incubation period. Under those same three conditions we also found that PCP dechlorination was enhanced by the addition of lactate, pyruvate, and acetate, but delayed by the addition of manganese oxide and inhibited by the addition of ferric chloride. In addition, our results failed to show any relationship between PCP dechlorination and oxidation-reduction potential (ORP) or changes in pH values. Treatment with lactate caused the greatest increase in methane production, the highest rates of sulfate or nitrate consumption; adding manganese oxide led to the second greatest increase, and the addition of ferric chloride the least. The addition of methylphenols and nitrophenols were found to inhibit PCP dechlorination. Methanogen may have constituted the major dechlorination population in our experimental consortium.