Krill oil prevents lipopolysaccharide-evoked acute liver injury in mice through inhibition of oxidative stress and inflammation.

Acute liver injury is a life-threatening syndrome that often results from the actions of viruses, drugs and toxins. Herein, the protective effect and potential mechanism of krill oil (KO), a novel natural product rich in long-chain n-3 polyunsaturated fatty acids bound to phospholipids and astaxanthin, on lipopolysaccharide (LPS)-evoked acute liver injury in mice were investigated. Male C57BL/6J mice were administered intragastrically with 400 mg kg-1 KO or fish oil (FO) once per day for 28 consecutive days prior to LPS exposure (10 mg kg-1, intraperitoneally injected). The results revealed that KO pretreatment significantly ameliorated LPS-evoked hepatic dysfunction indicated by reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and attenuated hepatic histopathological damage. KO pretreatment also mitigated LPS-induced hepatic oxidative stress, as evidenced by decreased malondialdehyde (MDA) contents, elevated glutathione (GSH) levels, and elevated catalase (CAT) and superoxide dismutase (SOD) activities. Additionally, LPS-evoked overproduction of pro-inflammatory mediators in serum and the liver was inhibited by KO pretreatment. Furthermore, KO pretreatment suppressed LPS-induced activation of the hepatic toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain containing 3 (NLRP3) signaling pathway. Interestingly, the hepatoprotective effect of KO was superior to that of FO. Collectively, the current findings suggest that KO protects against LPS-evoked acute liver injury via inhibition of oxidative stress and inflammation.

DHA-Enriched Phospholipids and EPA-Enriched Phospholipids Alleviate Lipopolysaccharide-Induced Intestinal Barrier Injury in Mice via a Sirtuin 1-Dependent Mechanism.

Intestinal barrier dysfunction has emerged as a potential contributor to the development of several severe diseases. Herein, the effect and underlying mechanism of DHA-enriched phospholipids (DHA-PL) and EPA-enriched phospholipids (EPA-PL) on protecting against lipopolysaccharide (LPS)-induced intestinal barrier injury were elucidated. C57BL/6J male mice were fed an AIN-93G diet containing 1% DHA-PL or EPA-PL for 4 weeks and then were intraperitoneally injected with LPS (10 mg/kg) to cause intestinal barrier injury. The results manifested that DHA-PL and EPA-PL pretreatment balanced apoptosis and autophagy in intestinal epithelial cells and maintained intestinal tight junction integrity. Our findings also demonstrated that cotreatment with EX-527, a sirtuin 1 specific inhibitor, hindered the role of DHA-PL and EPA-PL against LPS-evoked intestinal barrier injury through reversing the inhibitory action of them on NF-κB and MAPKs activation as well as their potentiating actions on Nrf2 nuclear translocation. Overall, DHA-PL and EPA-PL alleviated LPS-mediated intestinal barrier injury via inactivation of the NF-κB and MAPKs pathways as well as activating the Nrf2 antioxidant pathway via up-regulating sirtuin 1.

Docosahexaenoic acid-enriched phospholipids and eicosapentaenoic acid-enriched phospholipids inhibit tumor necrosis factor-alpha-induced lipolysis in 3T3-L1 adipocytes by activating sirtuin 1 pathways.

Some chronic diseases such as cancer-associated cachexia (CAC) and obesity are associated with the overproduction of tumor necrosis factor-alpha (TNF-α) that stimulates excess lipolysis in adipocytes. Our previous studies have shown that docosahexaenoic acid-enriched phospholipids (DHA-PL) and eicosapentaenoic acid-enriched phospholipids (EPA-PL) ameliorated CAC and obesity-related metabolic disorders. To identify the molecular mechanisms involved, we examined the impact and the associated signaling pathways of DHA-PL and EPA-PL on TNF-α-induced lipolysis in 3T3-L1 adipocytes. The present results revealed that DHA-PL and EPA-PL inhibited the TNF-α-induced increase of glycerol release and protected lipid droplets. In addition, DHA-PL and EPA-PL increased DHA and EPA contents in the phospholipid fraction of adipocytes, respectively. Moreover, DHA-PL and EPA-PL enhanced sirtuin 1 (SIRT1) deacetylase activity and its protein expression. By activating SIRT1, DHA-PL and EPA-PL upregulated the G0/G1 switch gene 2 protein level to inhibit adipose triglyceride lipase activity, activate AMP-activated protein kinase to reverse the downregulation of perilipin expression and phosphorylation of hormone-sensitive lipase (HSL) at Ser565 and prevent the phosphorylation of HSL at Ser660. Furthermore, DHA-PL and EPA-PL improved glucose uptake and glucose transporter type 4 translocation to the plasma membrane in TNF-α-treated adipocytes. Thus, it was concluded that DHA-PL and EPA-PL inhibit TNF-α-induced lipolysis in 3T3-L1 adipocytes by activating the SIRT1 pathways.

[Microbial Diversity and Influencing Factors in a Small Watershed in Winter].

The water quality of a small watershed will directly affect the water quality safety of the entire watershed. The Lidu small watershed of the Fulin District in Chongqing was selected for this study. The characteristics of runoff and the microbial community in the receiving water body were analyzed by high-throughput sequencing technology. The effects of the physical and chemical factors of the water body on the microbial diversity in the water body were also investigated. The results showed that the small watershed of Lidu was an important source of nitrite and dissolved organic carbon for the receiving water. There was no significant difference in the microbial richness and diversity of the water flowing through different pollution sources in the small watershed, and the microbial diversity index was negatively correlated with the total phosphorus (r -0.79--0.84, P ≤ 0.01) and phosphate (r -0.71--0.80, P ≤ 0.01) of the water. At the phylum level, Actinobacteria (37.33% ±14.69%) accounted for the largest proportion of runoff flowing through the agricultural area, followed by Proteobacteria (32.53% ±7.18%), Cyanobacteria (14.65% ±22.64%), Bacteroidetes (8.50% ±3.67%), and others. Proteobacteria (43.67% ±10.80%) accounted for the largest proportion of runoff flowing through the industrial area, followed by Bacteroidetes (25.33% ±11.97%), Actinobacteria (24.17% ±14.66%), Firmicutes (2.53% ±0.72%), and others. At the genus level, hgcI_clade (19.08% ±13.46%) accounted for the largest proportion of runoff flowing through the agricultural area, followed by CL 500-29 _marine_group (7.40% ±4.44%), Limnohabitans (7.05% ±3.14%), and others. Flavobacterium (20.40% ±12.37%) accounted for the largest proportion of runoff flowing through the industrial area, followed by hgcI_clade (15.30% ±11.11%), Acinetobacter (9.33% ±11.50%), and others. The Flavobacterium in the runoff water may be related to the input of industrial sources in the watershed. Nitrous nitrogen, total phosphorus, phosphate, pH, and Zn2+ were the main environmental factors that affected the microbial community in the small watershed. They can explain the variance of microbial community 0.26, 0.21, 0.20, 0.15, and 0.14, respectively. DOC, nitrate nitrogen, and heavy metal ions such as Cu2+, Zn2+, Mn2+, and As3+ were also related to the proportion of some microorganisms in the water.

A GIS-based multi-source and multi-box modeling approach (GMSMB) for air pollution assessment--a North American case study.

This article presents a GIS-based multi-source and multi-box modeling approach (GMSMB) to predict the spatial concentration distributions of airborne pollutant on local and regional scales. In this method, an extended multi-box model combined with a multi-source and multi-grid Gaussian model are developed within the GIS framework to examine the contributions from both point- and area-source emissions. By using GIS, a large amount of data including emission sources, air quality monitoring, meteorological data, and spatial location information required for air quality modeling are brought into an integrated modeling environment. It helps more details of spatial variation in source distribution and meteorological condition to be quantitatively analyzed. The developed modeling approach has been examined to predict the spatial concentration distribution of four air pollutants (CO, NO(2), SO(2) and PM(2.5)) for the State of California. The modeling results are compared with the monitoring data. Good agreement is acquired which demonstrated that the developed modeling approach could deliver an effective air pollution assessment on both regional and local scales to support air pollution control and management planning.

[Comparison of biological phosphorus removal between different systems using O2, NO3(-) and NO2(-) as electron acceptors].

By parallel operation of three phosphorus removal systems (SBR) using different electron acceptors of O2, NO3(-) and NO2(-), process characteristics and inherent competition mechanism of microorganisms were discussed. Although NO2(-) had no direct inhibition on anoxic phosphorus uptake after the DPAO cultivation, system performance was still much lower than that with NO3(-) as electron acceptor. And it ultimately resulted from the washout of the group of DPAO (DPAO5) that lacked the ability to denitrify NO2(-) and the enhanced GAO growth in the system. Being the efficient electron acceptor, NO3(-) or O2 supplying SBRs removed phosphorus smoothly and comparatively, in viewpoint of stiochoimetry and constitution of functional bacteria. In all three test systems, mass of GAO was present to exhaust limited organics with PAO population. Moreover, total PAO could be divided into 6 distinct groups, i.e., PO, PN, Pn, PNn, PON and PONn, based on the abilities of utilizing different electron acceptors. And facultative PAO of PON and PONn were found as the main contributors for the phosphorus removal. The higher ratio they accounted in sludge, the more capacity the system possessed to remove phosphorus, i.e., SBR0 > SBRn5 > SBRn3.

[Effect of intermittent aeration on growth kinetics of nitrifiers and mechanism for NO2- accumulation].

In order to investigate shortcut nitrification, an intermittent-aeration SBR was employed to treat the domestic wastewater containing low concentration of NH4+ . The results shows that under the SRTs of 10, 5, 2.5 and 1.25 d, NO2- produced in effluent were built up to 18, 19, 14 and 5 mg/L, respectively, with accumulation ratio of 73%, 85%, 91% and 78% respectively. As to the continuous-aeration SBR, however, the NO2- accumulation ratios were only 14%, 21%, 31% and 34%. In addition, the corresponding removals of NH4- in the intermittent-aeration SBR were maintained at a comparable level in contrast to those for the continuous-aeration SBR, i.e., 97%, 95%, 76% and 39% vs. 92%, 97%, 71% and 47%. By exploring the growth kinetics of nitrifiers, ammonia-oxidizing bacteria (AOB) in the intermittent-aeration system was capable of increasing its biomass in the reactor by an elevation in growth yield (Y(AOB)), which as a result compensated the decreased specific substrate utilization rate at low DO level and further led to the unchanged microm value and NH4+ oxidation rate. On the contrary, nitrite-oxidizin bacteria (NOB) was lack of the function of compensability, and it hence lowered the microm value and NO2-oxidation rate, and therefore resulted in an accumulation of NO2- in the effluent.

Factors affecting simultaneous nitrification and de-nitrification (SND) and its kinetics model in membrane bioreactor.

Experiments have been carried out to investigate the effect of biological factors such as dissolved oxygen (DO), food/microorganism (F/M) ratio, carbon/nitrogen (C/N) ratio and pH on performance of SND in membrane bioreactor (MBR). It was found that a low DO was advantageous to SND on condition that nitrification was not inhibited, while F/M ratio and C/N ratio have reverse effects on SND, and pH should also be controlled in a suitable range. Based on the conventional activated sludge model, a deduction was conducted to illustrate that SND could take place from the theoretical aspect, and it was proved that high organics was effective in improving SND. In addition, a kinetic model for SND was constituted on the basis of batch test result, and the simulation nitrate saturation coefficient K(NO)(3) was much higher than that in a single-sludge wastewater treatment system.

[Theoretical analysis and experimental research of ozone gas mass transfer efficiency in activated sludge].

Based on theoretical analysis, a mathematic model was primarily set up to describe the relationship between the ozone mass transfer efficiency (U) and the systematic factors, including sludge concentration, input gas concentration, mixed liquor height h, observed gas velocity u(obs) and the bubble diameter d. By different experimental design, furthermore, the contribution of these factors for transfer efficiency was investigated respectively. The results show that the mixed liquor height h and bubble diameter d impacted the mass transfer efficiency of ozone more significantly, as compared to the other factors of sludge concentration, input gas concentration and observed gas velocity u(obs). When mixed liquor height h was 0.2 m, the ozone gas utilization U was only 0.45; when h was 0.8 m, U increased to 0.883; when h was 1.4, U was almost up to 1. The U and h show strong index relationship. For mixed liquor with h 0.8 m, when bubble diameter d decreased from 0.007 5 to 0.005, U increased from 0.89 to 0.96, and, for mixed liquor with h 0.6 m, similar increase from 0.8 to 0.93 was observed. According to the acquired experimental data, a quantitative expression among mass transfer efficiency U, mixed liquor height h and mean bubble diameter d, with R2 equal to 0.861 6, was finally obtained, as a reference tool for project design.

Suspended particle effects on ClO2/ultraviolet light combined disinfection of effluent.

The concentration of suspended solids of effluent often varies in a wide range, therefore the dose of ultraviolet light (UV) in disinfection process needs to be adjusted to meet the disinfection criterion at a high frequency, and the desired disinfection effect is difficult to be ensured. The particles size and particle-associated fecal coliform (F.C.) contribution, and their influence on UV disinfection were investigated when ClO2 and UV combined disinfection process was used. The results showed that suspended solids content had a major impact on UV disinfection efficiency, especially the large particle size fraction. Particles (D>10 microm) associated F. C. were difficult to be disinfected and were the main part of the tailings of F.C. inactivation curve. Pre-ClO2 oxidation could reduce the number of particles in effluent, and make large particles decrease to small ones. Therefore, the influence of particles on UV disinfection could be reduced after pre-ClO2 oxidation, and the resistance ability to particle loadings of combined process was enhanced. Moreover, the combined process has a lot of advantages, such as low toxicity, low operational/maintenance costs; it is also convenient to be established in the existing wastewater plant or the new planned one.

Activated sludge ozonation to reduce sludge production in membrane bioreactor (MBR).

Total experimental period was divided into two stages. At first stage, a series of batch studies were carried out to get an understanding of the effect of ozonation on sludge properties. At the following stages, three membrane bioreactors (MBRs) with different amounts of activated sludge to be ozonated were run in parallel for a long period to evaluate the influence of sludge ozonation on sludge yield and permeate quality. Through batch study, it was found that ozone could disrupt the cell walls and cause the release of plasm from the cells, then the amounts of soluble organics in the solution increased with ozonation time. With the rise of soluble organics, the amount of soluble organics to be mineralized increased as well, which would reduce the soluble organics content. For the counteraction between these two aspects, a pseudo-balance could be achieved, and soluble organics would vary in a limited range. Sludge ozonation also increased the contents of soluble nitrogen and phosphorus in the solution. On the basis of batch study, a suitable ozone dosage of 0.16 kg O(3)/kg MLSS was determined. Three systems were run in parallel for a total period of 120 days; it was demonstrated that a part of activated sludge ozonation could reduce sludge production significantly, and biological performance of mineralization and nitrification would not be inhibited due to sludge ozonation. Experimental results proved that the combination of ozonation unit with MBR unit could achieve an excellent quality of permeate as well as a small quantity of sludge production, and economic analysis indicated that an additional ozonation operating cost for treatment of both wastewater and sludge was only 0.096 Yuan (US$ 0.0115)/m(3) wastewater.

Removal of nitrogen and phosphorus in a combined A2/O-BAF system with a short aerobic SRT.

A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A2/O-BAF) combined system was carried out to treat wastewater with lower C/N and C/P ratios. The A2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitrifying phosphate-accumulating organisms (DPAOs). The ratio of DPAOs to phosphorus accumulating organisms (PAOs) could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent return rates should be controlled with 1-4 mg/L nitrate nitrogen in the anoxic zone effluent of A2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies.

[Study on nitrogen cycling and transformations in a duckweed pond by means of modeling analysis].

Based on the simulated results from N cycling and transformation model of duckweed pond, the influences of different major transfer pathways on various nitrogen removal performances are investigated. The effects of seasonal variations of water conditions on nitrogen transformations are determined. The simulated results show that nitrification and denitrification were the major removal pathways for nitrogen in duckweed pond, and the removal contributions of organic nitrogen sedimentation and ammonia volatilization for total nitrogen removal were less than 2.1%. Furthermore, in duckweed pond, nitrification and denitrification decided the removal efficiencies of ammonia and NOx., respectively; both algae decaying and organic nitrogen ammonification controlled primarily the organic nitrogen removal performances; both organic nitrogen sedimentation and mineralization of sedimentary nitrogen determined the variations of sedimentary nitrogen. Duckweed pond with duckweed growing largely can increase sharply algae mortality and keep the low content of algae in effluent. Besides, through accelerating the nitrification and denitrification rate, duckweed can evidently improve the removal efficiencies of total nitrogen.

[Experiment study on real-time controlling rules of A/O nitrogen removal process].

The aim of this work is operational optimization of an A/O process in the lab plant with synthetic wastewater for improving nitrogen removal efficiency. Ammonia control aims at maintaining the required concentration of ammonia in the effluent by manipulating the dissolved oxygen (DO) set point and aeration volumes. Nitrate control aims at the optimal use of the denitrification potential at any moment by continuously adjusting the internal recirculation flow or (and) external carbon addition flow in order to maintain a desired nitrate set point in the anoxic zone. The control strategies have been based on a hierarchical structure where a high level or supervisory control selects the set point of the low level or conventional controllers. Results indicated that it was possible to increase nitrogen removal efficiency, improve the effluent water quality, save energy, and reduce operating costs.

Multi-stage ponds-wetlands ecosystem for effective wastewater treatment.

The performance of the Dongying multi-stage ponds-wetlands ecosystem was investigated in this work. Study of the removal of different pollutants (BOD(5), COD, SS, TP, TN, NH(3)-N, etc.) in different temperature seasons and different units in this system indicated that effluent BOD(5) and SS were constant to less than 11 mg/L and 14 mg/L throughout the experimental processes; but that the removal efficiencies of pollutants such as TP, TN, NH(3)-N, COD varied greatly with season. The higher the temperature was, the higher was the observed removal in this system. Additionally, each unit of the system functioned differently in removing pollutants. BOD(5) and SS were mainly removed in the first three units (hybrid facultative ponds, aeration ponds and aerated fish ponds), whereas nitrogen and phosphates were mainly removed in hydrophyte ponds and constructed reed wetlands. The multi-stage ponds-wetlands ecosystem exhibits good potential of removing different pollutants, and the effluent quality meet several standards for wastewater reuse.

Performance of a subsurface-flow constructed wetland in southern China.

The operational performance of a full-scale subsurface-flow constructed wetland, which treated the mixed industrial and domestic wastewater with BOD5/COD mean ratio of 0.33 at Shatian, Shenzhen City was studied. The constructed wetland system consists of screens, sump, pumping station, and primary settling basin, facultative pond, first stage wetland and secondary stage wetland. The designed treatment capacity is 5000 m3/d, and the actual influent flow is in the range of < 2000 to > 10000 m3/d. Under normal operational conditions, the final effluent quality well met the National Integrated Wastewater Discharge Standard (GB 8978-1996), with the following parameters(mean values): COD 33.90 mg/L, BOD, 7.65 mg/L, TSS 7.92 mg/L, TN 9.11 mg/L and TP 0.56 mg/L. Seven species of plants were selected to grow in the wetland: Reed, Sweetcane flower Silvergrass, Great Bulrush, Powdery Thalia and Canna of three colours. The growing season is a whole year-round. The seasonal discrepancy could be observed and the plants growing in the wetland are vulnerable to lower temperature in winter. The recycling of the effluent in the first stage of the wetland system is an effective measure to improve the performance of the wetland system. The insufficient DO value in the wetland system not only had significant effect on pollutants removal in the wetland, but also was unfavourable to plant growth. The recycling of effluent to the inlet of wetland system and artificial pond to increase DO value of influent to the wetland is key to operate the subsurface constructed wetland steadily and effectively.

Determination of operational parameters of anaerobic phase for enhanced phosphorus removal in MBR.

Two runs of experiments were carried out to obtain an understanding of phosphorus release and uptake under the anaerobic condition and then the aerobic condition respectively. Under anaerobic condition, it was found that the extent of phosphorus release appeared to increase with the increase of the initial organic loading rate when the initial organic loading rate was up to 0.1 gSCOD/gMLSS. When the initial organic loading rate was higher than 0.1 gSCOD/gMLSS, the amount of phosphorus release per unit mass of MLSS reached nearly a same stationary value, and it seemed this is not affected by organic loading rate when there is external available substrate remained. In addition, the effect of NOx-N on the phosphorus release and uptake was also investigated, it was proved that the denitrifiers has an advantage over polyphosphate accumulating bacteria in competition for organic substrate under anoxic condition. Therefore, the existence of NOx-N is disadvantageous to the phosphorus release. Based upon the above investigations, the process configuration of membrane bioreactor(MBR) in combination with anaerobic phase was proposed to enhance the removal of phosphorus in treating domestic wastewater. During the experimental period of four months, average removals of 92.50%, 84.25%, 100%, 94.09% and 85.33% were achieved for COD, TP, SS, NH3-N and TN respectively.

[Effects of Chinese herb compound on myocardial SDH, ATP-ase and energy reserves in tail-suspended rats].

OBJECTIVE: To investigate effects of Chinese herb compound on myocardial SDH, ATP-ase and energy reserves in tail-suspended rats. METHOD: Male SD rats were randomly divided into three groups (n=10 each): (A) normal control group; (B) tail-suspended group; (C) tail-suspended + Chinese Medical herb compound group. Rats in group B and C were tail-suspended (-30 degrees) for 5 d to simulate weightlessness. All rats B were decapitated after the experiment. Myocardial SDH (method of Anderson N-BT), ATP-ase (method of Wachstein and Meisel) and energy reserves (method of HPLC) were examined. RESULT: Compared with rats in groups A and C, SDH activity increased, SDH staining deepened, value of OD SDH enhanced, ATP-ase activity and OD value increased and enhanced significantly (P<0.01) but value of myocardial energy reserves decreased in group B rats. CONCLUSION: Tail-suspension strengthens compensatory oxidation metabolism of cardiac muscle and activates SDH and ATP-ase, at the same time decrease, myocardial energy reserves. Normal are maintained the low level of metabolism by the medical herb compound used which shows a protecting effects through mitigation, tranguilization and replenishment of Qi.

Biological nitrogen removal with enhanced phosphate uptake in (AO)2 SBR using single sludge system.

Simultaneous biological phosphorus and nitrogen removal with enhanced anoxic phosphate uptake via nitrite was investigated in an anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR). The system showed stable phosphorus and nitrogen removal performance, and average removals for COD, TN and TP were 90%, 91% and 96%, respectively. The conditions of pH 7.5-8.0 and temperature 32 degrees C were found detrimental to nitrite oxidation bacteria but favorable to ammonia oxidizers, and the corresponding specific oxygen uptake rates(SOUR) for phase 1 and 2 of nitrification process were 0.7 and 15 mgO2/(gVSS x h) in respect, which led to the nitrite accumulation in aerobic phase of (AO)2 SBR. Respiratory tests showed that 40 mgNO2-N/L did not deteriorate the sludge activity drastically, and it implied that exposure of sludge to nitrite periodically enabled the biomass to have more tolerance capacity to resist the restraining effects from nitrite. In addition, batch tests were carried out and verified that denitrifying phosphorus accumulation organisms (DPAOs) could be enriched in a single sludge system coexisting with nitrifiers by introducing an anoxic phase in an anaerobic-aerobic SBR, and the ratio of the anoxic phosphate uptake capacity to aerobic phosphate uptake capacity was 45%. It was also found that nitrite (up to 20 mgNO2-N/L) was not inhibitory to anoxic phosphate uptake and could serve as an electron acceptor like nitrate, but presented poorer efficiency compared with nitrate.