Objective To evaluate the surgical strategy of decompression via posterior-anterior approach and anterior fixation in treatment fracture-dislocation of the lower cervical spine with bilateral facet joints dislocation. Methods This study retrospectively reviewed 37 cases of lower cervical spine fracture with bilateral joints dislocation. There were 21 males and 16 females with an average age of 42 years (19-58). Distraction-flexion stage 3(DFS 3) were found in 24 cases and DFS 4 in 13 cases. All the cases were diagnosed by X-ray, CT and MRI and confirmed during the surgery. Decompression via posterior-anterior approach and anterior fixation had been adapted as the surgical strategy. The NASCIS and IMSOP standard were applied to definite the level of cervical spinal cord injury. The ASIA grading was used for evaluation the spinal cord function and the recovery rate. The X-ray and CT were used to observe reduction and bone fusion. Results The mean operative time was (4.5:±0.5) h, and the mean amount of blood loss was 360 ml (200-500 ml). All the incision healed. The two segments fixation was used in 23 cases, 3 segments fixation in 13 cases, and 4 segments fixation in 1 case. The mean follow-up period was 32 months (16-45 months).Postoperative X-ray and CT showed that bone fusion was achieved in all patients within 4-8 months, without graft displacement, or failure of implants. Spinal cord function did not aggravate, and sensory recovery ranged from 7 to 20 levels (averaged, 12.7). The ASIA grade were improved with an average of one grade. Conclusion To treat fracture-dislocation of the lower cervical spine with bilateral facet joints dislocation, the posterlor-anterior approach and anterior fixation/fusion was benefit to preservation the cervical spinal cord function and reconstruction biomechanical stability of the cervical spine.

Heterotrophic nitrification-aerobic denitrification (HN-AD) is an enrichment and breakthrough theory of traditional autotrophic nitrification heterotrophic denitrification. Heterotrophic nitrification-aerobic denitrifiers with the feature of wide distribution, strong adaptability and unique metabolic mechanism have many special advantages, including fast-growing, rapid biodegradability and long lasting activity, which can rapidly remove ammonia nitrogen, nitrate nitrogen (NO₃⁻-N) and nitrite nitrogen (NO₂⁻-N) under aerobic conditions simultaneously. Therefore, HN-AD bacteria show the important potential for denitrification under extreme conditions with high-salt, low-temperature or high-ammonia nitrogen environment, and HN-AD bacteria attract extensive attention in the field of biological denitrification of wastewater. In this review, we first introduce the previously reported HN-AD bacterial species which have denitrification performance in the extreme environments and state their typical metabolic mechanism. Then, we systematically analyze the nitrogen removal characteristics and potential under extreme conditions. We also briefly describe the progress in the application of HN-AD bacterial. Finally, we outlook the application prospects and research directions of HN-AD denitrification technology.
Aerobiosis ; Bacteria ; Denitrification ; Heterotrophic Processes ; Nitrification ; Nitrites ; Nitrogen

We isolated and enriched mixed microorganisms SWA1 from landfill cover soils supplemented with trichloroethylene (TCE). The microbial mixture could degrade TCE effectively under aerobic conditions. Then, we investigated the effect of copper ion (0 to 15 μmol/L) on TCE biodegradation. Results show that the maximum TCE degradation speed was 29.60 nmol/min with 95.75% degradation when copper ion was at 0.03 μmol/L. In addition, genes encoding key enzymes during biodegradation were analyzed by Real-time quantitative reverse transcription PCR (RT-qPCR). The relative expression abundance of pmoA gene (4.22E-03) and mmoX gene (9.30E-06) was the highest when copper ion was at 0.03 μmol/L. Finally, we also used MiSeq pyrosequencing to investigate the diversity of microbial community. Methylocystaceae that can co-metabolic degrade TCE were the dominant microorganisms; other microorganisms with the function of direct oxidation of TCE were also included in SWA1 and the microbial diversity decreased significantly along with increasing of copper ion concentration. Based on the above results, variation of copper ion concentration affected the composition of SWA1 and degradation mechanism of TCE. The degradation mechanism of TCE included co-metabolism degradation of methanotrophs and oxidation metabolism directly at copper ion of 0.03 μmol/L. When copper ion at 5 μmol/L (biodegradation was 84.75%), the degradation mechanism of TCE included direct-degradation and co-metabolism degradation of methanotrophs and microorganisms containing phenol hydroxylase. Therefore, biodegradation of TCE by microorganisms was a complicated process, the degradation mechanism included co-metabolism degradation of methanotrophs and bio-oxidation of non-methanotrophs.
Biodegradation, Environmental ; Copper ; chemistry ; Methylocystaceae ; metabolism ; Oxidation-Reduction ; Soil Microbiology ; Trichloroethylene ; metabolism