Composite Membrane with Underwater-Oleophobic Surface for Anti-Oil-Fouling Membrane Distillation

In this study, we fabricated a composite membrane for membrane distillation (MD) by modifying a commercial hydrophobic polyvinylidene fluoride (PVDF) membrane with a nanocomposite coating comprising silica nanoparticles, chitosan hydrogel and fluoro-polymer. The composite membrane exhibits asymmetric wettability, with the modified surface being in-air hydrophilic and underwater oleophobic, and the unmodified surface remaining hydrophobic. By comparing the performance of the composite membrane and the pristine PVDF membrane in direct contact MD experiments using a saline emulsion with 1000 ppm crude oil (in water), we showed that the fabricated composite membrane was significantly more resistant to oil fouling compared to the pristine hydrophobic PVDF membrane. Force spectroscopy was conducted for the interaction between an oil droplet and the membrane surface using a force tensiometer. The difference between the composite membrane and the pristine PVDF membrane in their interaction with an oil droplet served to explain the difference in the fouling propensities between these two membranes observed in MD experiments. The results from this study suggest that underwater oleophobic coating can effectively mitigate oil fouling in MD operations, and that the fabricated composite membrane with asymmetric wettability can enable MD to desalinate hypersaline wastewater with high concentrations of hydrophobic contaminants

Cellular immune response in chickens infected with avian infectious bronchitis virus (IBV)

To understand the mechanistic basis of innate immunity against the infectious bronchitis virus (IBV), the gene transcription profile of pattern recognition receptors (PRRs) in SPF chicken tissues infected with an IBV-M41 strain was examined. IBV infection induced mRNA transcription of TLRs, RLRs, and NODs. TLR7, MyD88, TRAF6, MDA5, LGP2, and NLRC5 were stimulated, as well as mRNA activation of the downstream genes of NF-κB and IRF3. And mRNA for the pro-inflammatory cytokines of interferon-α (IFN)-α, IFN-β, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) showed over-expression. The IBV load in tissues gradually reduced. These results suggested that the three kinds of PRRs signaling pathways and innate immune cytokine were induced after IBV infection

An ultrasonic assisted direct contact membrane distillation hybrid process for desalination

A novel ultrasonic assisted direct contact membrane distillation (USDCMD) hybrid process was designed and the effects of feed temperature, feed concentration, feed velocity, ultrasonic power and frequency on mass transfer were investigated. Under ultrasonic irradiation, changes and damages in membrane structure were found on PVDF membrane, while the pore size and the stretching strain of PP fibers were also enlarged and declined, respectively. The PTFE hollow fiber was selected to carry out USDCMD. The results showed that ultrasonic irradiation could effectively enhance mass transfer. Under the ultrasonic irradiation of 20 kHz and 260 W, the maximum permeate flux enhancement of 60% was obtained under conditions of feed temperature of 53 degrees C, feed velocity of 025 m/s and feed salt concentration of 140 g/L. The increment was enlarged with the decrease of feed temperature, feed velocity and ultrasonic frequency as well as the increase of feed concentration and ultrasonic power. Ultrasonic irradiation had no significant influence on the mechanical strength, pore size and hydrophobicity of the FIFE membrane in a 240 h continuous USDCMD experiment, and the novel membrane distillation process exhibited satisfying performance stability, which indicated that ultrasonic irradiation can be applied to membrane distillation for mass transfer enhancement. (C) 2014 Elsevier B.V. All rights reserved

A novel microwave assisted photo-catalytic membrane distillation process for treating the organic wastewater containing inorganic ions

A novel microwave assisted photo-catalytic membrane distillation (MPMD) process was proposed in this study to treat organic wastewater containing inorganic ions. Humic acid (HA) solution containing Ca2+ was used as feed to investigate the effects of microwave irradiation and ultraviolet (UV) radiation on the MD process. The membrane surface and composition of the fouling layer was studied using scanning electron microscopy (SEM) coupled with energy dispersion spectrometry (EDS). Ca2+ affected the permeation flux by forming complex compounds with humic acids and resulted in coagulation on the membrane surface in a conventional MD process. Microwave irradiation effectively decreased the deposit on membrane surface by destabilizing complex compounds. Organic matter was photo-degraded by the microwave assisted photo-catalysis so that the membrane fouling was prevented. In the MPMD process, the flux remained nearly constant. After 45 h of operation with the continuously concentrated solution, the concentration of the solution in photocatalytic reactor was about 2.8 times than the initial and J/J(0) equaled to 94.5%. In the end of MPMD process, J/J(0) equaled to 98.5%. The conductivity of the distillate over the operation time was less than 4 mu Scm(-1). MPMD was used to treat the coal gasification wastewater. The results clearly demonstrated that the MPMD process was sufficient to treat the coal gasification wastewater with a removal rate higher than 96% for CODcr and 98% for NH4+-N after an operation over 120 h. (C) 2015 Elsevier Ltd. All rights reserved

Punicalagin Induces Nrf2/HO-1 Expression via Upregulation of PI3K/AKT Pathway and Inhibits LPS-Induced Oxidative Stress in RAW264.7 Macrophages

Reactive oxygen species (ROS) and oxidative stress are thought to play a central role in potentiating macrophage activation, causing excessive inflammation, tissue damage, and sepsis. Recently, we have shown that punicalagin (PUN) exhibits anti-inflammatory activity in LPS-stimulated macrophages. However, the potential antioxidant effects of PUN in macrophages remain unclear. Revealing these effects will help understand the mechanism underlying its ability to inhibit excessive macrophage activation. Hemeoxygenase-1 (HO-1) exhibits antioxidant activity in macrophages. Therefore, we hypothesized that HO-1 is a potential target of PUN and tried to reveal its antioxidant mechanism. Here, PUN treatment increased HO-1 expression together with its upstream mediator nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). However, specific inhibition of Nrf2 by brusatol (a specific Nrf2 inhibitor) dramatically blocked PUN-induced HO-1 expression. Previous research has demonstrated that the PI3K/Akt pathway plays a critical role in modulating Nrf2/HO-1 protein expression as an upstream signaling molecule. Here, LY294002, a specific PI3K/Akt inhibitor, suppressed PUN-induced HO-1 expression and led to ROS accumulation in macrophages. Furthermore, PUN inhibited LPS-induced oxidative stress in macrophages by reducing ROS and NO generation and increasing superoxide dismutase (SOD) 1 mRNA expression. These findings provide new perspectives for novel therapeutic approaches using antioxidant medicines and compounds against oxidative stress and excessive inflammatory diseases including tissue damage, sepsis, and endotoxemic shock