[Occurrence Characteristics, Sources, and Toxicity Risk Analysis of Polycyclic Aromatic Hydrocarbons in Typical Rivers of Northern Shaanxi Mining Area, China].

The aim of this study was to assess the occurrence level, spatial distribution, pollution source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in the Kuye River of the northern Shaanxi mining area. In total, 16 priority PAHs were quantitatively detected at 59 sampling sites using a high-performance liquid chromatography-diode array detector in series with a fluorescence detector. The results showed that the ρ(ΣPAHs) in the Kuye River ranged from 50.06 to 278.16 ng·L-1, with an average value of 128.22 ng·L-1. The PAHs monomer concentrations ranged from 0 to 121.22 ng·L-1, of which Chrysene had the highest concentration, with average values of 36.58 ng·L-1, respectively, followed by benzo(a)anthracene and phenanthrene. The detection rate of each monomer was more than 70%, of which 12 monomers revealed detection rates of 100%. In addition, the 4-ring PAHs showed the highest relative abundance in the 59 samples, ranging from 38.59% to 70.85%. The PAHs concentrations revealed significant spatial variation in the Kuye River. Moreover, the highest PAHs concentrations were mainly observed in coal mining, industrial, and densely populated areas. Compared with those in other rivers in China and worldwide, the PAHs concentrations in the Kuye River showed a medium pollution level. On the other hand, the positive definite matrix factorization (PMF) and diagnostic ratios were used to quantitatively assess the source apportionment of PAHs in the Kuye River. The results showed that coking and petroleum emissions, coal combustion, fuel-wood combustion, and automobile exhaust emissions contributed to the PAHs concentrations in the industrial areas of the upper reach by 34.67%, 30.62%, 18.11%, and 16.60%, and coal combustion, fuel-wood combustion, and automobile exhaust emissions contributed in the downstream residential areas by 64.93%, 26.20%, and 8.86%. In addition, the results of the ecological risk assessment showed low ecological risks of naphthalene and high ecological risks of benzo(a)anthracene, respectively, whereas the remaining monomers revealed medium ecological risk. Among the 59 sampling sites, only 12 belonged to low ecological risk areas, whereas the remaining sampling sites were at medium to high ecological risks. Moreover, the water area near the Ningtiaota Industrial Park showed a risk value close to the high ecological risk threshold. Therefore, it is urgent to formulate prevention and control measures in the study region.

A Newly Isolated Strain Lysobacter brunescens YQ20 and Its Performance on Wool Waste Biodegradation.

Wool keratin is difficult to degrade as comparing to feathers because of its tough secondary structure. In order to develop an approach for high-value utilization of wool fiber waste by keratinolytic microorganisms, which is produced from shearing, weaving, and industrial processing of wool, screening of wool-degrading bacterium with high degradation efficiency were performed in this study. To this end, Lysobacter brunescens YQ20 was identified and characterized. The optimized conditions for wool degradation were pH 9.0 and 37°C with 20% liquid volume of Erlenmeyer flask. After fermentation, 15 essential amino acids were detected when wool fiber waste was fermented. The total amino acids produced from 1% wool per hour were 13.7 mg/L. The concentration was 8.6-fold higher than that produced by the strain Stenotrophomonas maltophilia BBE11-1, which had previously been reported to have the highest wool-degrading capacity. Our study reports the first Lysobacter strain that exhibits efficient wool degradation and yields higher concentrations of amino acids than previously reported strains. Whole-genome sequencing indicated that there were 18 keratinase-like genes in the genome of YQ20, which exhibited a long evolutionary distance from those of Bacillus. Therefore, L. brunescens YQ20 may have applications in the environmentally friendly management of wool waste as fertilizer in agriculture.

Pseudohalioglobus sediminis sp. nov., isolated from coastal sediment.

A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, designated NY5T, was isolated from marine sediment collected from coastal area in Weihai, China (122°07' 38.80'' E, 37°33' 57.60'' N). Cells of strain NY5T were 0.6-0.7 µm width and 1.9-2.0 µm length, catalase-positive and oxidase-positive. Growth of NY5T was observed at 25-37 °C (optimum, 28 °C) and pH 6.5-9.5 (optimum, pH 7.5-8.0) and in the presence of 0.5-7.0% (w/v) NaCl (optimum, 2.0%). The isoprenoid quinone was Q-8 and the predominant fatty acids were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and C17:1 ω8c. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids. The DNA G+C content of strain NY5T was 60.1%. Strain NY5T showed the highest 16S rRNA gene sequence similarity (98.2%) with Pseudohalioglobus lutimaris followed by Parahaliea aestuarii (96.9%), Parahaliea maris (96.7%), Parahaliea mediterranea (95.9%), and Halioglobus japonicus (94.9%). Given these phenotypic and chemotaxonomic properties and phylogenetic analyses, strain NY5T was considered to represent a novel species of the genus Pseudohalioglobus, for which the name Pseudohalioglobus sediminis sp. nov. is proposed. The type strain is NY5T (=KCTC 72416T=MCCC 1H00401T).

Case Report: Adult degenerative scoliosis in two patients treated with percutaneous spinal endoscopic-assisted lumbar interbody fusion and percutaneous pedicle screw fixation.

Adult degenerative scoliosis (ADS) is a serious disease that often affects middle-aged and elderly people. ADS does not only cause sagittal and coronal deformity of the lumbar spine but also causes severe back and leg pain secondary to the compression of the neural structures. Open surgery remains the main method for correcting the occurring deformity and decompression of the neural structures; however, its benefit is limited in cases of large trauma. Minimally invasive spinal (MIS) surgery is an alternative method that has recently witnessed rapid development. It has the advantage of providing rapid recovery with less trauma as compared to conventional open surgery. We report two cases of ADS treated with percutaneous spinal endoscopic-assisted lumbar interbody fusion (EALIF) and percutaneous pedicle screw fixation. Both cases had moderate deformities of the lumbar spine (load-sharing classification 4-7 points) with severe back and leg pain, and they underwent successful MIS surgery. At 6 months of follow-up, the visual analog scale and Oswestry disability index scores of both patients improved and the deformity was corrected. For moderate ADS, percutaneous spinal EALIF and percutaneous pedicle screw fixation may achieve an effective correction of the deformity with direct decompression of neural structures.

Palleronia sediminis sp. nov. and Flavivirga algicola sp. nov., two marine bacteria isolated from offshore areas near Weihai.

Two bacterial strains, designated SS33T and Y03T, were isolated from marine sediment and marine red alga collected on the coast of Weihai, PR China. Based on the results of 16S rRNA gene sequence analysis, strain SS33T was found to be closely related to Primorskyibacter marinus PX7T, Pelagivirga dicentrarchi YLY04T, Palleronia marisminoris DSM 26347T and Maribius pontilimi GH1-23T with 94.8, 94.6, 94.5 and 94.5 % sequence similarity; strain Y03T was found to be closest to Flavivirga aquimarina EC2D5T, Flavivirga eckloniae ECD14T and Flavivirga amylovorans JC2681T with 96.4, 96.1 and 96.0 % sequence similarity. Strain SS33T grew at 4-37 °C (optimum, 33 °C), at pH 6.0-9.5 (optimum, pH 7.5-8.0) and in the presence of 0-10 % (w/v) NaCl (optimum, 3.0 %). Chemotaxonomic analysis of strain SS33T showed that the predominant respiratory quinone was ubiquinone-10. The major fatty acids (>10.0 %) included C18 : 1 ω7c and C16 : 0. The major polar lipids included phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, one unidentified glycolipid, one unidentified polar lipid and two unidentified aminolipids. Strain Y03T grew at 15-40 °C (optimum, 28 °C), at pH 6.5-8.0 (optimum, pH 7.0) and in the presence of 0.5-9.0 % (w/v) NaCl (optimum, 2.0%). Chemotaxonomic analysis showed that the predominant respiratory quinone was menaquinone-6. The major fatty acids (>10.0 %) included iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and iso-C15 : 0 3-OH. The major polar lipids included phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and four unidentified polar lipids. Based on the polyphasic data, strain SS33T is considered to represent a novel species of the genus Palleronia, for which the name Palleronia sediminis sp. nov. is proposed, with the type strain SS33T (=KCTC 62986T=MCCC 1H00387T). Strain Y03T is considered to represent a novel species of the genus Flavivirga, for which the name Flavivirga algicola sp. nov. is proposed, with the type strain Y03T (=KCTC 72001T=MCCC 1H00386T).

[Treatment of atlanto-axial vertebral instability fractures with cervical posterior pedicle screw internal fixation and interbody fusion].

OBJECTIVE: To explore the clinical effects of cervical posterior pedicle screw internal fixation and interbody fusion for the treatment of atlanto-axial vertebral instability fractures. METHODS: From July 2008 to July 2013, 21 patients with atlanto-axial vertebral instability fractures were treated with vertebral pedicle screw internal fixation and interbody fusion through posterior approach. There were 14 males and 7 females, aged from 20 to 55 years old with an average of 32 years. Lifted and guided the atlanto-axial vertebral pedicle screw to reduce atlanto-axial vertebral displacement. RESULTS: All patients were followed up from 6 to 24 months with an average of 12.5 months. Wounds got healed without complication of infection. Clinical symptoms were relieved at 6 months after operation. According to ASIA score standard to assess at 6 months after operation, the items of motion, light touch and needle score had obviously improved, and respectively were 99.45 ±0.27, 111.09 ± 0.47,111.11 ± 0.58. VAS and NDI scores also had obviously improved, and respectively were 1.04 ± 0.38 and 12.56 ± 2.24. Imaging examinations showed internal fixation locations were good, without atlanto-axial joint instability. CONCLUSION: Cervical posterior pedicle screw internal fixation and interbody fusion can effectively restore the stability of atlanto-axial joint, reduce complication and obtain satisfactory effects.

[Cloning and expression of a outer membrance protein gene(OmpS(2);) of Edwardsiella tarda HB01 and its immunogenicity].

AIM: To construct a recombinant strain BL21(DE3)(pET-28a-OmpS(2);), and obtain a genetic engineering vaccine to provide protective immunity against diseases caused by Edwardsiella tarda. METHODS: According to the GenBank sequences (GenBank Accession No. AY078509), one pair of primers was designed and the outer membrance protein gene (OmpS(2);) of Edwardsiella tarda HB01 was amplified by PCR. The OmpS(2); gene was cloned in pET-28a vector and transformed into Escherichia coli BL21(DE3). The OmpS(2); protein was highly expressed when the recombinant strain BL21 (DE3) (pET-28a-OmpS(2);) was induced by IPTG. The expressed protein was 47 kD as estimated by 150 g/L SDS-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The immunogenicity of the expressed OmpS(2); protein was confirmed by Western blotting. Mice and Paralichthys olivaceus were immunized with the genetic engineering vaccines of Edwardsiella tarda and Aeromonas hydrophila, showing promise that all these vaccines have a high protective ability. And the protective ability to Edwardsiella tarda and Aeromonas hydrophila in Paralichthys olivaceus respectively reached 70% and 80%. CONCLUSION: The recombinant strain BL21 (DE3)(pET-28a-OmpS(2);) could be candidate of genetic engineering vaccine to provide protective immunity against diseases caused by Edwardsiella tarda.

[The influence of the redox conditions on the three-dimensional excitation-emission matrix (3DEEM) fluorescence spectroscopy of the dissolved organic matter (DOM) in the overlying water].

In the present study three-dimensional excitation-emission matrix (3DEEM) fluorescence spectroscopy was applied to characterize the dissolved organic matter (DOM) in the overlying water under aerobic and anaerobic condition. The effects of redox condition were significant on 3DEEM fluorescence spectra of DOM, and in the aerobic condition, the peak intensities of protein-like fluorophores were both higher than those of the humic-like fluorophores, however, the phenomenon of the oxidative degradation of humic-original DOM could be seen. While in anaerobic condition, the peak intensities of the humic-like fluorescence were increased with increasing the incubation time. After the 21 day anaerobic incubation, the peak intensities of the humic-like fluorescence can be as 3.51 and 3.78 times higher than those of protein-like fluorescence. The differences in the DOM fluorescence parameters, e.g., peak intensities, locations and fluorescence index, indicate the difference in the chemical structures and various origins of the DOM in the overlying water between sediment-water interfaces.