Periodic and Spatial Spreading of Alkanes and Alcanivorax Bacteria in Deep Waters of the Mariana Trench.

In subduction zones, serpentinization and biological processes may release alkanes to the deep waters, which would probably result in the rapid spread of Alcanivorax However, the timing and area of the alkane distribution and associated enrichment of alkane-degrading microbes in the dark world of the deep ocean have not been explored. In this study, we report the richness (up to 17.8%) of alkane-degrading bacteria, represented by Alcanivorax jadensis, in deep water samples obtained at 3,000 to 6,000 m in the Mariana Trench in two cruises. The relative abundance of A. jadensis correlated with copy numbers of functional almA and alkB genes, which are involved in alkane degradation. In these water samples, we detected a high flux of alkanes, which probably resulted in the prevalence of A. jadensis in the deep waters. Contigs of A. jadensis were binned from the metagenomes for examination of alkane degradation pathways and deep sea-specific pathways, which revealed a lack of nitrate and nitrite dissimilatory reduction in our A. jadensis strains. Comparing the results for the two cruises conducted close to each other, we suggest periodic release of alkanes that may spread widely but periodically in the trench. Distribution of alkane-degrading bacteria in the world's oceans suggests the periodic and remarkable contributions of Alcanivorax to the deep sea organic carbon and nitrogen sources.IMPORTANCE In the oligotrophic environment of the Mariana Trench, alkanes as carbohydrates are important for the ecosystem, but their spatial and periodic spreading in deep waters has never been reported. Alkane-degrading bacteria such as Alcanivorax spp. are biological signals of the alkane distribution. In the present study, Alcanivorax was abundant in some waters, at depths of up to 6,000 m, in the Mariana Trench. Genomic, transcriptomic, and chemical analyses provide evidence for the presence and activities of Alcanivorax jadensis in deep sea zones. The periodic spreading of alkanes, probably from the subductive plates, might have fundamentally modified the local microbial communities, as well as perhaps the deep sea microenvironment.

[Features of functional MRI in children with oppositional defiant disorder].

OBJECTIVE: To determine the characteristics of functional magnetic resonance imaging in brain of children with oppositional defiant disorder (ODD)when performing an impulsive task and to explore the brain structure of impulsivity. METHODS: Ten ODD children and 10 age and sex-matched control children were recruited. The stimulus task with GOSTOP impulsivity paradigm software was used as the mode of stimulus-rest-stimulus. The data of 2 groups were normalized, merged, and averaged, and then the activation regions were compared by SPM software. RESULTS: More scattered cortex and subcortex regions were activated in the ODD group than in the control group during the performance of an impulsive task. The activated cortex in the control group focused on the frontal pole (including inferior frontal gyrus, middle frontal gyrus and orbital-frontal gyrus) and temporal pole (including inferior temporal gyrus and middle temporal gyrus). CONCLUSION: Frontal pole may be an important region related to multiplicity impulsivity, and shows hypofunction in ODD children.

[Preliminary clinical application of percutaneous vertebroplasty].

OBJECTIVE: To investigate the clinical application of percutaneous vertebroplasty (PVP). METHODS: PVP was performed in 21 cases of 37 vertebral lesions,including 14 osteoporotic compression fractures, 6 metastases, 1 hemangioma,and 17 lesions in thoracic vertebra and 20 in lumbar. The procedures of PVP were as follows: The needle was inserted via percutaneous transpedicular approach or percutaneous posterolateral vertebral approach; the needle tip was placed at the junction of the anterior located the one third of the vertebral body; intraosseous venography was performed; and last bone cement was injected at 2-10 mL. The technical success rate, clinical efficacy and complications were observed after the procedure. Results The procedure was successful in 18 cases with 31 lesions,and the success rate according to the number of cases and vertebral lesions was 85.7% (18/21) and 83.8% (31/37), respectively. After the procedure, the numbers of complete remission, partial remission, mild remission and no remission were 10, 5, 2 and 1, respectively; and the total effective rate was 94.4% (17/18). Progressive compression did not occur. Three patients had transient neuropathy and recovered after physiotherapy. Other complications were insignificant; no severe complications occurred. Conclusion PVP is an effective and micro-traumatic treatment for patients with benign and malignant lesions in vertebral bodies.