[Anaerobic Biodegradability of Perfluorooctanoic Acid (PFOA)].

Perfluorooctanoic acid (PFOA), one of the most typical representatives of perfluoroalkyl surfactants (PASs), has relatively high detection rate and level of pollution, and the accumulation of PFOA in the environment has been a serious threat to human health and security of the whole ecological environment. Therefore, studies on anaerobic biodegradability of PFOA are very important for elucidation of its environmental fate. This study used anaerobic sludge from municipal sewage treatment plant (WWTP) and 5.0 mg·L-1 vitamin B12 (VB12) as catalysts for the degradation of PFOA in the anaerobic environment. The anaerobic biodegradability of PFOA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) and ion chromatography while some indictors, such as molar recoveries of PFOA as well as concentrations of fluoride, acetate, 2H-PFOA (F(CF2)6CHFCOOH), and shorter chain (

[Case-control studies on complex tibial plateau and posterior condylar fractures treated through combined anterior-posterior (small incision or micro-incision) approach].

OBJECTIVE: To study the therapeutic effects of combined anterior-posterior (small incision or micro-incision) approach for complex tibial plateau and posterior condylar fractures. METHODS: From 2000 to 2008, 79 patients (81 limbs) with complex tibial plateau and posterior condylar fractures were reviewed. There were 45 males and 34 females, ranging in age from 19 to 66 years, with an average of 40.6 years. Thirty-nine limbs were treated using small incision through combined anterior-posterior approach, in which 13 limbs were Schatzker type IV, 15 limbs were type V ,and 11 limbs were type VI. Other 42 limbs were treated using micro-incision through combined anterior-posterior approach, in which 18 limbs were Schatzker type IV, 16 limbs were type V, and 8 limbs were type VI. The Rasmussen scores for knee joint and radio scores were used to evaluate therapeutic effects after the treatment. The complications such as cutaneous necrosis and incision infection were observed. RESULTS: All the patients were followed up. According to Rasmussen criterion, in small incision group, 16 limbs got an excellent result, 13 good, 7 fair and 3 bad; in micro-incision group,above data were 19, 11, 8 and 4 respectively. Comparison between the two groups, P = 0.924. Comparison of complications such as cutaneous necrosis and incision infection: in small incision group,10 limbs had the complications, and in micro-incision group were 4 limbs; the occurrence rate of small incision group were higher than that of micro-incision group (P = 0.047). CONCLUSION: There are no significant differences between the two groups in the knee joint function rehabilitation; however, there is smaller rate for cutaneous necrosis and incision infection in micro-incision group.