RESUMO
Oil spills have an important threat to the ecological security and human health, for example the important oil field and coastal wetland Yellow River Delta is facing the dual problems of oil pollution and salinization. Therefore, the purpose of this study was to analyze the changes of soil microbial community and physicochemical properties, including pH value, total organic carbon (TOC), total petroleum hydrocarbons (TPHs) and electrical conductivity under the combined effect of petroleum and salinization. The soil properties results showed that the petroleum addition promoted the increase of TOC from 2.31 ± 0.59 mg/kg to 7.04 ± 0.42 mg/kg (r > 0.95, P < 0.1, R2 > 0.9), TPHs from 9.18 ± 0.07 mg/kg to 33.09 ± 4.61 mg/kg (r > 0.9, P < 0.05, R2 > 0.9) significantly. At the initial stage hydrocarbons caused the increase of soil salt content and the decrease of pH. Salt addition increased soil salt from 2.46 ± 0.13 g/kg to 15.12 ± 0.21 g/kg (r > 0.8, P > 0.1, R2 > 0.95), but it had no direct effect on other soil properties. It was found that the nitrate reducing bacteria Halorhodospiraceae with potential petroleum degradation ability and the anaerobic bacteria Lactobacilliceae appeared after adding crude oil. The salt tolerant bacteria Halobacilli and the stone oil degrading bacteria Immundisolidcharacter appeared in the high salt and low salt environments respectively. The aerobic bacteria Acidimicrobiaceae, Hyphomonas and the nonoil efficient Peptoccaceae disappeared in the process of salinization and oil pollution. Lactobacilliceae can ferment carbohydrate, fatty acid or ester to produce lactic acid, acetic acid and fumaric acid to provide metabolic substrate for other microorganisms. The above results showed that sensitive microorganisms were easy to be affected by pollution to indicate soil conditions, while tolerant microorganisms could potentially use oil to achieve bioremediation. The soil properties and microbial results provided data support and theoretical basis for further understanding the pollution mechanism of oil and salinization combined stress on soil.
Assuntos
Biodegradação Ambiental , Poluição por Petróleo , Microbiologia do Solo , Poluentes do Solo/análise , Bactérias/metabolismo , China , Poluentes Ambientais/metabolismo , Hidrocarbonetos/análise , Microbiota , Petróleo/análise , Rios , Solo/química , Áreas AlagadasRESUMO
OBJECTIVE:To compare the efficacy and safety of low molecular weight heparin and rivaroxaban in the preven-tion of deep venous thrombosis after spinal surgery. METHODS:Totally 276 patients with high risk factors after spinal surgery were randomly divided into control group and observation group. The patients in the two groups were used elastic stockings to physi-cally prevent deep venous thrombosis from the postoperative first day to continue 3 months;based on it,control group was subcuta-neously injected with 1 low molecular weight heparin from the postoperative first day,once a day. Observation group was orally treated with 1 Rivaroxaban tablet,once every night. The treatment course for 2 groups was 2 weeks. The clinic data was observed, including clinical efficacy,superficial femoral vein diameter(FSV),popliteal vein diameter(POPV),prothrombin time(PT),fi-brinogen degradation products(FIB)and D- dimer(DD)before and after treatment,incidence of deep venous thrombosis and ad-verse reactions. RESULTS:There were no significant differences in the total effective rate and deep venous thrombosis and inci-dence of ADR between 2 groups(P>0.05). After 3 months,compared with before,there were no significant differences in the FSV and POPV between 2 groups (P>0.05);POPV in control group was significantly lower than before and observation group, there was statistical significance(P0.05);the FIB and D-D were significantly higher than before,there was statistical significance(P0.05);after 4 weeks,PT in 2 groups was significantly high-er than before,there was statistical significance(P0.05);FIB and D-D were significantly higher than before,and observation group was lower than control group,there was statisti-cal significance(P<0.05). CONCLUSIONS:Both efficacy and safety of low molecular weight heparin and rivaroxaban in the pre-vention of deep venous thrombosis after spinal surgery are good. However,rivaroxaban is better than low molecular weight heparin in improving blood coagulation function.