The linkage between methane production activity and prokaryotic community structure in the soil within a shale gas field in China.

Soil methane generation mainly driven by soil prokaryotic microbes can be coupled with the degradation of petroleum hydrocarbons (PHCs); however, the relationship between prokaryotic community structure and methane production activity in soil with the potential risk of PHC contamination is seldom reported. In this study, 3 soil samples (CS-1 to CS-3) in the area nearby an exploratory gas well and 5 soil samples (DC-1 to DC-5) in a drill cutting dump area were obtained from the Fuling shale gas field (Chongqing City, China). Then, the prokaryotic community structure was examined by Illumina Miseq sequencing, and the linkage between soil methane production rate (MPR) and prokaryotic community composition was analyzed. The results indicated that 2 samples (DC-4 and DC-5) collected from the drill cutting dump area had significantly higher MPR than the other samples, and a significant and positive relationship (r = 0.44, P < 0.05) was found between soil MPR and soil organic matter (OM) content. The prokaryotic community composition in the sample (DC-5) with the highest MPR was different from those in the other samples, and soil OM and MPR were the major factors significantly correlated with the prokaryotic community structure in this soil. The samples (DC-4 and DC-5) with higher MPR had a higher relative abundance of Archaea and different archaeal community structures from the other samples, and the MPR was the sole factor significantly correlated with the archaeal genus composition in this soil. Therefore, both the prokaryotic and archaeal community structures are essential in the determination of soil MPR, and the bacterial genus of Saccharibacteria and the archaeal genus of Methanolobus might be the key contributors for methane generation in this soil from the shale gas field.

Transurethral endoscopic submucosal en bloc dissection for nonmuscle invasive bladder cancer: A comparison study of HybridKnife-assisted versus conventional dissection technique.

SUBJECTS: The aim of this study is to compare the efficacy and safety of en bloc bladder tumor-endoscopic submucosal dissection (BT-ESD) and conventional transurethral resection of BT (TURBT) in nonmuscle invasive bladder cancer (NMIBC) patients. METHODS: A retrospective cohort study was carried out in Shaanxi Provincial People's Hospital. A total of 193 eligible NMIBC (Ta/T1) patients were enrolled in this study (95 cases in BT-ESD group and 98 cases in TURBT group), between November 2013 and January 2017. The operation time, blood loss, postoperative bladder irrigation time, catheter indwelling time, hospital stay time, and complications were compared. Data were presented as median (range). Chi-squared or rank-sum test, two-way ANOVA, and Mantel-Cox (Log-Rank) test were performed using statistical software. A threshold of P < 0.05 was defined as statistically significant. RESULTS: The average operation time in the BT-ESD group was longer than that of in the TURBT group (40.0 [5.0, 100.0] min vs. 19.5 [3.0, 55.5] min); however, no significant longer operating time (P < 0.05) were observed in the smaller tumor (0 cm-3 cm). The postoperative bladder irrigation time, catheter indwelling time, and hospital stay in BT-ESD group were significantly shorter than that of in TURBT group (9.0 [5.0, 18.0] h, 2.5 [1.0, 4.0] d and 3.5 [2.0, 5.0] d for BT-ESD; 18.0 [12.0, 48.0] h, 3.5 [2.0, 7.0] d, and 4.5 [3.0, 8.0] d for TURBT). In addition, the BT-ESD group showed the decreased overall incidence of complications (2.1% vs. 9.2%). The univariate and multivariate analyses indicated an association between surgical option and tumor recurrence (hazard ratio = 5.624, odds ratio = 95% confidence interval = 1.582-19.991), Kaplan-Meir analysis showed significant difference in recurrence-free survival (RFS) (94.7% for ESD group vs. 78.4% for TURBT group) at 33 months. CONCLUSIONS: The application of the HybridKnife lead to a decrease in complications and RFS rate, which was a more safe and effective approach for NMIBC than conventional TURBT.

[Investigation of the Coupling Mechanism Between Naphthalene Degradation and Denitrification of a Naphthalene Degraded Bacterial Consortium Under Denitrification].

To investigate the coupling mechanism between naphthalene degradation and denitrification using a liquid media containing naphthalene (sole carbon source) and nitrate, a naphthalene degradation bacterial consortium under denitrification was enriched from a soil with potential risk of PAH (polycyclic aromatic hydrocarbon) contamination. The bacterial community composition of the enriched consortium was analyzed by Illumina MiSeq Sequencing. Subsquently, the enriched consortium was cultured under anaerobic conditions for 9 days, and the concentrations of electron acceptors (nitrate and nitrite) for denitrification, gaseous reduction products (N2O and N2) involved in denitrification, and abundances of denitrification concerned genes (narG:periplasmic nitrate reeducates gene; nirS:cd1-nitrite reductase gene) were detected at days 1, 3, 7, and 9. The result of Illumina MiSeq Sequencing showed that Pseudomonas (Proteobacteria) was the most dominant genus in this enriched consortium. Under anaerobic conditions, the naphthalene removal rate of this enriched consortium was 49.11% within 9 days. Relative higher naphthalene degradation rates were found both at the beginning (day 1-3) and the end (day 7-9) of incubation, and these were significantly higher than at the middle (day 3-7) of the incubation stage (P<0.05). The concentration of nitrate decreased during the whole culture period, while the concentration of nitrite increased during the initial incubation (day 1-3) and rapidly decreased from day 3 to 9. Furthermore, obvious productions of N2O[3.39 µg ·(L ·h)-1] and N2[8.97 µg ·(L ·h)-1] were only measured at the end of incubation (day 7-9). The abundances of both narG and nirS increased during the incubation, indicating the continuous growth of denitrifiers in the enriched consortium during the incubation period. In summary, this study illustrated that both the nitrate reducing stage and gas producing steps of denitrification could be coupled with anaerobic naphthalene degradation, which might be helpful for a deeper investigation regarding the coupling mechanism between denitrification and anaerobic PAH degradation.

[Environmental geochemical baseline of heavy metals in soils of the Ili river basin and pollution evaluation].

Environmental geochemical baseline models of Cu, Zn, Pb, As, Hg were established by standardized method in the ehernozem, chestnut soil, sierozem and saline soil from the Ili river valley region. The theoretical baseline values were calculated. Baseline factor pollution index evaluation method, environmental background value evaluation method and heavy metal cleanliness evaluation method were used to compare soil pollution degrees. The baseline factor pollution index evaluation showed that As pollution was the most prominent among the four typical types of soils within the river basin, with 7.14%, 9.76%, 7.50% of sampling points in chernozem, chestnut soil and sierozem reached the heavy pollution, respectively. 7.32% of sampling points of chestnut soil reached the permitted heavy metal Pb pollution index in the chestnut soil. The variation extent of As and Pb was the largest, indicating large human disturbance. Environmental background value evaluation showed that As was the main pollution element, followed by Cu, Zn and Pb. Heavy metal cleanliness evaluation showed that Cu, Zn and Pb were better than cleanliness level 2 and Hg was the of cleanliness level 1 in all four types of soils. As showed moderate pollution in sierozem, and it was of cleanliness level 2 or better in chernozem, chestnut soil and saline-alkali soil. Comparing the three evaluation systems, the baseline factor pollution index evaluation more comprehensively reflected the geochemical migration characteristics of elements and the soil formation processes, and the pollution assessment could be specific to the sampling points. The environmental background value evaluation neglected the natural migration of heavy metals and the deposition process in the soil since it was established on the regional background values. The main purpose of the heavy metal cleanliness evaluation was to evaluate the safety degree of soil environment.

[Over-expression of hypoxia-inducible factor-1alpha induces epithelial-mesenchymal transition in LNCaP cells in vitro and in vivo].

OBJECTIVE: To investigate the effects of the over-expression of hypoxia-inducible factor-1alpha (HIF-1alpha) on the epithelial-mesenchymal transition (EMT) and invasive potency of LNCaP cells in vitro and in vivo. METHODS: We cultured LNCaP cells stably expressing HIF-1alpha (LNCaP/HIF-1alpha) and LNCaP cells, identified the over-expression of HIF-1alpha, determined the proliferation of the two cell lines by MTT assay and the level of PSA in the supernatant of culture medium, and detected the anchorage independent growth by soft-agar colony formation assay. A subcutaneous tumor model was established in nude mice by injecting LNCaP/HIF-1alpha and LNCaP cells followed by observation of the tumor growth. Tumor specimens were obtained for immunohistochemistry. RESULTS: The over-expression of HIF-1alpha was confirmed in the LNCaP/HIF-1alpha cells by immunofluorescence staining and Western blotting. The level of PSA was obviously decreased in LNCaP/HIF-1alpha as compared with that in LNCaP cells. MTT assay identified the increased proliferation of LNCaP/HIF-1alpha cells. The cell colony forming ability of the LNCaP cells was significantly lower than that of the LNCaP/HIF-1alpha cells. The rate of tumorigenesis was increased and its time shortened in the LNCaP/HIF-1alpha group. Immunohistochemistry revealed an up-regulated expression of vimentin and a down-regulated expression of E-cadherin in the tumor specimens. CONCLUSION: The overexpression of HIF-1alpha can up-regulate the expression of vimentin and down-regulate the expression of E-cadherin, which may enhance the invasive potency of LNCaP cells by inducing EMT.