Mixing of plant litters strengthens their remediation effects on crude oil-contaminated soil.

To investigate the effects of the mixing of litters on their remediation efficiency in petroleum-contaminated soil, litters from two common plants in the petroleum-contaminated region of Northern Shaanxi, China, Bothriochloa ischaemum (L.) Keng and Sophora davidii Kom. ex Pavol., and their mixture were mixed with 45 g/kg petroleum-contaminated soil. Based on these, a 150-day simulated remediation experiment was conducted at 25 °C and consistent moisture conditions. The effects on the degradation of petroleum components and the restoration of nutrient contents, pH, and enzymatic activity in the disturbed soil were detected. The effects of the litter treatments on the community structure and carbon source utilization characteristics of soil microorganisms were also studied. The results indicated that all litter treatments significantly accelerated the degradation of petroleum components, while the mixing of litter exhibited significant synergistic effects, leading to significantly higher degradation rates of saturated hydrocarbons, aromatic hydrocarbons, and nonhydrocarbon substances than the observed rates in the single-litter treatments and the predicted rates based on the single-litter treatments. Litter treatment significantly increased the N and P contents and enzymatic activity of contaminated soil. The effects of mixed litter on soil chemical and biological properties fell between the effects of the 2 types of single-litter treatments. However, the mixing of litters exhibited significant synergistic effects in supplementing available P and increasing sucrase, dehydrogenase, lignin peroxidase, and laccase activity, while it exhibited significant antagonistic effects in supplementing nitrate nitrogen and increasing urease, phosphatase, polyphenol oxidase, and manganese peroxidase activity. Litter treatment significantly altered the community structure of soil microorganisms. The relative abundances of some petroleum-degrading microbial phyla or genera in mixed litter-treated soil were significantly different from those in single litter-treated soils, which might contribute to the strengthened remediation effects of mixed litter treatment. The results might provide a theoretical basis for the more effect utilization of biomass resources in the remediation of petroleum-contaminated soil.

Dynamics of the remediating effects of plant litter on the biological and chemical properties of petroleum-contaminated soil.

To investigate the comprehensive remediating effects of plant residues on biological and chemical properties and the long-term dynamics of these effects, litter from Caragana korshinskii (caragana) or Ziziphus jujuba var. spinosa (jujube) was mixed with three types of soil that were contaminated with 12.49, 27.54, and 45.37 g kg-1 of petroleum. The mixtures were incubated at 20-25 °C with consistent soil moisture for 360 days. Subsequently, the litter impacts on the soil microbial population, the activities of 12 types of soil hydrolytic, and redox enzymes related to the cycling of C, N, and P, and the available N, P, and K contents were determined during the incubation. The results indicated that both types of litter significantly accelerated the reproduction of soil microbes and significantly increased the activities of most of the hydrolytic enzymes and the available nutrient contents after the short-term treatments, while the litters usually simultaneously depressed the activities of polyphenol oxidase and peroxidase in the slightly and moderately contaminated soils. However, the comprehensive remediating effects of the litters on the lightly contaminated soil significantly decreased over time while it recovered to some extent at the end of the experiment. The remediating effects on the seriously contaminated soil exhibited the opposite trend, and their remediating effects on the moderately contaminated soil exhibited continuous weakening. Generally, the remediating effects of the caragana litter were more noticeable than those of the jujube litter, except for the effect on the slightly contaminated soil after 180 days of treatment.

[Status of diagnosis and management of acute appendicitis in 2017: a national multi-center retrospective study].

OBJECTIVE: To analyze the current status of diagnosis and management of acute appendicitis (AA) in China. METHODS: Questionnaire survey was used to retrospectively collect data of hospitalized patients with AA from 43 medical centers nationwide in 2017 (Sort by number of cases provided: Jinling Hospital of Medical School of Nanjing University, The First Affiliated Hospital of Xinjiang Medical University, Lu'an People's Hospital, Tengzhou Central People's Hospital, Dalian Central Hospital, The Affiliated Hospital of Xuzhou Medical University, Dongying People's Hospital, Jinjiang Hospital of Traditional Chinese Medicine, Huangshan Shoukang Hospital, Xuyi People's Hospital, Nanjing Jiangbei People's Hospital, Lanzhou 940th Hospital of PLA, Heze Municipal Hospital, The First College of Clinical Medical Science of China Three Gorges University, Affiliated Jiujiang Hospital of Nanchang University, The Second People's Hospital of Hefei, Affiliated Central Hospital of Shandong Zaozhuang Mining Group, The Third People's Hospital of Kunshan City, Xuzhou First People's Hospital, The 81st Group Army Hospital of PLA, Linyi Central Hospital, The General Hospital of Huainan Eastern Hospital Group, The 908th Hospital of PLA, Liyang People's Hospital, The 901th Hospital of Joint Logistic Support Force, The Third Affiliated Hospital of Chongqing Medical University, The Fourth Hospital of Jilin University, Harbin Acheng District People's Hospital, The First Affiliated Hospital of Zhengzhou University, Nanjing Luhe People's Hospital, Taixing Municipal People's Hospital, Baotou Central Hospital, The Affiliated Hospital of Nantong University, Linyi People's Hospital, The 72st Group Army Hospital of PLA, Zaozhuang Municipal Hospital, People's Hospital of Dayu County, Taixing City Hospital of Traditional Chinese Medicine, Suzhou Municipal Hospital, Beijing Guang'anmen Hospital, Langxi County Hospital of Traditional Chinese Medicine, Nanyang Central Hospital, The Affiliated People's Hospital of Inner Mongolia Medical University).The diagnosis and management of AA were analyzed through unified summary. Different centers collected and summarized their data in 2017 and sent back the questionnaires for summary. RESULTS: A total of 8 766 AA patients were enrolled from 43 medical centers, including 4 711 males (53.7%) with median age of 39 years and 958 (10.9%) patients over 65 years old. Of 8 776 patients, 5 677 cases (64.6%) received one or more imaging examinations, and the other 3 099 (35.4%) did not receive any imaging examination. A total of 1 858 (21.2%) cases received medical treatment, mainly a combination of nitroimidazoles (1 107 cases, 59.8%) doublet regimen, followed by a single-agent regimen of non-nitroimidazoles (451 cases, 24.4%), a nitroimidazole-free doublet regimen (134 cases, 7.2%), a triple regimen of combined nitroimidazoles (116 cases, 6.3%), nitroimidazole alone (39 cases, 2.1%) and nitroimidazole-free triple regimen (3 cases, 0.2%). Of the 6 908 patients (78.8%) who underwent surgery, 4 319 (62.5%) underwent laparoscopic appendectomy and 2589 (37.5%) underwent open surgery. Ratio of laparotomy was higher in those patients under 16 years old (392 cases) or over 65 years old (258 cases) [15.1%(392/2 589) and 10.0%(258/2 589), respectively, compared with 8.5%(367/4 316) and 8.0%(347/4 316) in the same age group for laparoscopic surgery, χ²=91.415, P<0.001; χ²=15.915,P<0.001]. Patients with complicated appendicitis had higher ratio of undergoing open surgery as compared to those undergoing laparoscopic surgery [26.7%(692/2 589) vs. 15.6%(672/4 316), χ²=125.726, P<0.001].The cure rates of laparoscopic and open surgery were 100.0% and 99.8%(2 585/2 589) respectively without significant difference (P=0.206). Postoperative complication rates were 4.5%(121/2 589) and 4.7%(196/4 316) respectively, and the difference was not statistically significant (χ²=0.065, P=0.799). The incidence of surgical site infection was lower (0.6% vs. 1.7%, χ²=17.315, P<0.001), and hospital stay was shorter [6(4-7) days vs. 6(5-8) days, U=4 384 348.0, P<0.001] in the laparoscopic surgery group, while hospitalization cost was higher (median 12 527 yuan vs. 9 342 yuan, U=2 586 809.0, P<0.001). CONCLUSIONS: The diagnosis of acute appendicitis is still clinically based, supplemented by imaging examination. Appendectomy is still the most effective treatment at present. Laparoscopic appendectomy has become the main treatment strategy, but anti-infective drugs are also very effective.