ABSTRACT
In industrial wastewater treatment, organic pollutants are usually removed by in-situ microorganisms and exogenous bactericides. Benzo [a] pyrene (BaP) is a typical persistent organic pollutant and difficult to be removed. In this study, a new strain of BaP degrading bacteria Acinetobacter XS-4 was obtained and the degradation rate was optimized by response surface method. The results showed that the degradation rate of BaP was 62.73% when pH= 8, substrate concentration was 10 mg/L, temperature was 25 °C, inoculation amount was 15% and culture rate was 180 r/min. Its degradation rate was better than that of the reported degrading bacteria. XS-4 is active in the degradation of BaP. BaP is degraded into phenanthrene by 3, 4-dioxygenase (α subunit and ß subunit) in pathway â and rapidly forms aldehydes, esters and alkanes. The pathway â ¡ is realized by the action of salicylic acid hydroxylase. When sodium alginate and polyvinyl alcohol were added to the actual coking wastewater to immobilize XS-4, the degradation rate of BaP was 72.68% after 7 days, and the removal effect was better than that of single BaP wastewater (62.36%), which has the application potential. This study provides theoretical and technical support for microbial degradation of BaP in industrial wastewater.
Subject(s)
Environmental Pollutants , Wastewater , Biodegradation, Environmental , Benzo(a)pyrene/metabolism , Environmental Pollutants/metabolism , Bacteria/metabolismABSTRACT
The production of organic fertilizer by aerobic composting of cattle manure is an important way of its resource utilization. This study evaluated the effects of adding mature compost on the decomposition and microbial communities in the aerobic composting of cattle manure. The addition of mature compost shortens the composting cycle and results in a final lignocellulosic degradation rate of 35%. Metagenomic analysis showed that this was due to the proliferation of thermophilic and organic matter-degrading functional microorganisms, which enhanced the activity of carbohydrate-active enzymes. With the addition of mature compost, the microbial community exhibited stronger metabolic functions, especially carbohydrate and amino acid metabolism, which are the driving forces of organic matter degradation. This study deepens the understanding of organic matter conversion and microbial community metabolic functions when mature compost is used for livestock manure composting and provides a promising technology for livestock manure composting.
Subject(s)
Composting , Microbiota , Cattle , Animals , Soil , Manure , CarbohydratesABSTRACT
OBJECTIVE: To provide an overview of prediction models for the risk of major depressive disorder (MDD) among older adults. METHODS: We conducted a systematic review combined with a meta-analysis and critical appraisal of published studies on existing geriatric depression risk models. RESULTS: The systematic search screened 23,378 titles and abstracts; 14 studies including 20 prediction models were included. A total of 16 predictors were selected in the final model at least twice. Age, physical health, and cognitive function were the most common predictors. Only one model was externally validated, two models were presented with a complete equation, and five models examined the calibration. We found substantial heterogeneity in predictor and outcome definitions across models; important methodological information was often missing. All models were rated at high or unclear risk of bias, primarily due to methodological limitations. The pooled C-statistics of 12 prediction models was 0.83 (95%CI=0.77-0.89). CONCLUSION: The usefulness of all models remains unclear due to several methodological limitations. Future studies should focus on methodological quality and external validation of depression risk prediction models.
Subject(s)
Depressive Disorder, Major , Humans , Aged , Depressive Disorder, Major/diagnosis , Depression/diagnosis , ForecastingABSTRACT
Selenium (Se) is critical for human health, but human intake of Se is often inadequate. Organic forms of dietary Se are considered safe and more bioavailable than inorganic forms. Along with a generally high nutritional value, sprouts are sensitive to Se treatment. This study used selenomethionine and methylselenocysteine solutions to cultivate Se-enriched sprouts under an optimized hydroponic condition. Content change and transformations of the selenoamino acids were analyzed by a developed HPLC-ESI-MS/MS method. Uptake of both selenomethionine and methylselenocysteine was dose-dependent and involved active transport and passive diffusion, as demonstrated by the respiratory and aquaporin inhibition assays. Passive diffusion played a dominant role. Free methylselenocysteine was the predominant form in samples. Selenomethionine and methylselenocysteine were capable of mutual transformation. Moreover, the selenoprotein generation was associated with the increasing Se concentration of the culture solutions. The results provided scientific references for the efficient utilization of organic Se in sprouts.
Subject(s)
Organoselenium Compounds , Raphanus , Antacids , Organoselenium Compounds/chemistry , Raphanus/chemistry , Selenomethionine/chemistry , Selenoproteins/chemistry , Tandem Mass Spectrometry , Vitamins/analysisABSTRACT
In this study, we developed and validated a liquid chromatography triple quadrupole tandem mass spectrometry (LC-MS/MS) method used to simultaneously determine levels of four fluoroquinolones (ofloxacin, norfloxacin, lomefloxacin, and pefloxacin) and two antipsychotics (diazepam and methaqualone) in fish and shrimp. The samples were extracted with a mixture of anhydrous sodium sulfate and acetonitrile, and purified by C18 cartridge solid-phase extraction with an optimized eluent. The MS2 method was applied to recognize the molecular structure of these compounds according to a main fragmentation scheme. The key ions of identification and quantification were deduced from chemical structures. Multiple reaction monitoring was used to quantitatively analyse the compounds of interest. Satisfactory linearities were obtained (R2 ≥0.99) with the limits of quantitation (LOQs) ranging between 0.03 and 1.96 µg kg-1. The recoveries were 74-122%, with a relative standard deviation (RSD) below 4.9% for these compounds at the spiking level of three, five, and ten times the LODs, respectively. The LC-MS/MS method allows precise and sensitive determination of residues of six important banned veterinary drugs in fish and shrimp tissue. This methodological approach solved the problem imposed by the need for two or more analysis methods to analyse the compounds of interest described in this study.
Subject(s)
Antipsychotic Agents , Tandem Mass Spectrometry , Animals , Chromatography, High Pressure Liquid , Chromatography, Liquid , Crustacea , Fishes , Fluoroquinolones/analysis , Solid Phase ExtractionABSTRACT
Anaerobic co-digestion of excess sludge (ES) and different varieties of rice straw including indica rice straw (IRS), japonica rice straw (JRS) and glutinous rice straw (GRS) was investigated in batch and semi-continuous experiments. The batch experiment results showed that the GRS addition presents the highest hydrolysis and methanogenesis rates, its cumulative methane yield (CMY) was 305.75 mL/g VS and its average methane content was 60.56%. After digestion, the structure of GRS was almost completely destroyed, which was beneficial to the degradation of lignocellulose. The digestive process is affected by the abundance of Actinobactereria, Proteobacteria, Methanosaetae and Methanosarcina. The results of semi-continuous digestion were similar to batch digestion. In addition, the addition of GRS increased TN concentration in biogas residue and TP concentration in biogas slurry, but was not conducive to the subsequent dehydration of sludge.
Subject(s)
Oryza , Sewage , Anaerobiosis , Biofuels , Bioreactors , MethaneABSTRACT
Objective To identify the characteristics of anesthesia and perioperative management for ankylosing spondylitis (AS) patients undergoing total hip arthroplasty (THA). Methods Totally 63 patients scheduled for single THA in PUMC Hospital from January 1st 2013 to June 1st 2015 were included in this retrospective analysis,among whom 21 patients were diagnosed of AS. The perioperative clinical data included:demographic data,American Society of Anesthesiologists (ASA) classification,medical history,airway assessment,preoperative laboratory examinations,electrocardiogram,pulmonary function tests,intubation information,operation time,intraoperative intake and output volume,postoperative hospital stay,and postoperative complications. Results Significantly fewer AS patients undergoing THA were evaluated as ASA classification I than non-AS patients (9.5% vs. 33.3%,P=0.041). AS patients had significantly higher level of preoperative high-sensitivity C-reactive protein [(17.0±14.8)mg/L vs.(4.3±7.1)mg/L,P<0.001],platelets [(275.0±71.3)×10(9)/L vs. (237.7±68.0)×10(9)/L,P=0.048] and neutrophils [(4.7±1.7)×10(9)/L vs. (3.9±1.4)×10(9)/L,P=0.044] and higher incidence of pulmonary function abnormality (42.9% vs.16.7%,P=0.024).More AS patients were induced with scoline (14.3% vs.0,P=0.012). More AS patients underwent THA with Mallampati classification 3 (28.6% vs.7.1%,P=0.022),reduced neck extension(47.6% vs.2.4%,P<0.001),Cormack-Lehane classification2(56.3% vs.15.4%,P=0.002)and 3 (18.8% vs.0,P=0.005),while much fewer AS patients had Cormack-Lehane classification1 (25.0% vs.84.6%,P<0.001).A variety of difficult airway tools were used in intubation (AS group:Macintosh laryngoscope:14%,Macintosh laryngoscope with stylet:38%,visualization laryngoscope:24%,visualization stylet:10% and fiber bronchoscope:14%;non-AS group:57%,24%,12%,5% and 2%,respectively). The use of intraoperative autologous blood transfusion (33.3% vs.11.9%,P=0.041) and postoperative 24 h drainage (61.9% vs.31.0%,P=0.019) were more common in AS group. However,no statistical difference existed in the success rate of first intubation,postoperative hemoglobin,postoperative hematocrit,and postoperative hospitalization(all P>0.05). Conclusions AS patients undergoing THA have elevated preoperative inflammatory markers,with high incidence of pulmonary function abnormality and difficult airway. In consideration of high risk of surgery and anesthesia,adequate airway evaluation and optimization of perioperative management are needed to ensure the patients' safety.