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Find video protocols related to scientific articles indexed in Pubmed.
miR-21 Attenuates Human Cytomegalovirus Replication in Neural Cells by Targeting Cdc25a.
J. Virol.
PUBLISHED: 11-08-2014
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Congenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects, primarily manifesting as neurological disorders. HCMV infection alters expression of cellular microRNAs and induces cell-cycle arrest, which in turn modifies the cellular environment to favor virus replication. Previous observations found that HCMV infection reduces miR-21 expression in neural progenitor/stem cells (NPCs). Here, we show that infection of NPCs and U-251MG cells represses miR-21 while increasing levels of Cdc25a, a cell cycle regulator and known target of miR-21. These opposing responses to infection prompted an investigation of the relationship between miR-21, Cdc25a, and viral replication. Overexpression of miR-21 in NPCs and U-251MG cells inhibited viral gene expression, genome replication, and production of infectious progeny, while shRNA-knockdown of miR-21 in U-251MG cells increased viral gene expression. In contrast, overexpression of Cdc25a in U-251MG cells increased viral gene expression and production of infectious progeny and overcame the inhibitory effects of miR-21 overexpression. Three viral gene products, IE1, pp71, and UL26, were shown to inhibit miR-21 expression at the transcriptional level. These results suggest that Cdc25a promotes HCMV replication and elevation of Cdc25a levels post HCMV infection are due in part to HCMV-mediated repression of miR-21. Thus, miR-21 is an intrinsic antiviral factor that is modulated by HCMV infection. This suggests a role for miR-21 downregulation in the neuropathogenesis of HCMV infection of the developing CNS.
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High-yield Harvest of Nanofibers/Mesoporous Carbon Composite by Pyrolysis of Waste Biomass and Its Application for High Durability Electrochemical Energy Storage.
Environ. Sci. Technol.
PUBLISHED: 11-06-2014
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Disposal and recycling of the large scale biomass waste is of great concern. Themochemically converting the waste biomass to functional carbon nanomaterials and bio-oil is an environmentally-friendly apporach by reducing greenhouse gas emissions and air pollution caused by open burning. In this work, we reported a scalable, "green" method for the synthesis of the nanofibers/mesoporous carbon composites through pyrolysis of the Fe(III)-preloaded biomass, which is controllable by adjustment of temperature and additive of catalyst. It is found that the coupled catalytic action of both Fe and Cl species is able to effectively catalyze the growth of the carbon nanofibers on the mesoporous carbon and form magnetic nanofibers/mesoporous carbon composites (M-NMCCs). The mechanism for the growth of the nanofibers is proposed as an in-situ vapor deposition process, and confirmed by the XRD and SEM results. M-NMCCs can be directly used as electrode materials for electrochemical energy storage without further separation, and exhibit favorable energy storage performance with high EDLC capacitance, good retention capability, and excellent stability and durability (more than 98% capacitance retention after 10,000 cycles). Considering that biomass is a naturally abundant and renewable resource (over billions tons biomass produced every year globally) and pyrolysis is a proven technique, M-NMCCs can be easily produced at large scale and become a sustainable and reliable resource for clean energy storage.
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Analysis of poly-?-hydroxyalkonates (PHA) during the enhanced biological phosphorus removal process using FTIR spectroscopy.
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 11-01-2014
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Enhanced biological phosphorus removal (EBPR) is the main phosphorus removal technique for wastewater treatment. During the anaerobic-aerobic alternative process, the activated sludge experienced the anaerobic storage of polyhydroxy-?-alkonates (PHA) and aerobic degradation, corresponding the infrared peak intensity of sludge at 1 740 cm(-1) increased in the aerobic phase and declined in the anaerobic phase. Compared with PHA standard, this peak was indentified to attribute the carbonyl of PHA. The overlapping peaks of PHA, protein I and II bands were separated using Gaussian peak fitting method. The infrared peak area ratios of PHA versus protein I had a good relationship with the PHA contents measured by gas chromatography, and the correlation coefficient was 0.873. Thus, the ratio of the peak area of PHA versus protein I can be considered as the indicator of the PHA content in the sludge. The infrared spectra of 1 480-1 780 cm(-1) was selected, normalized and transferred to the absorption data. Combined with the chromatography analysis of PHA content in the sludge sample, a model between the Fourier-transform infrared spectroscopy (ETIR) spectra of the sludge and PHA content was established, which could be used for the prediction of the PHA content in the unknown sample. The PHA content in the sludge sample could be acquired by the infrared spectra of the sludge sample and the established model, and the values fitted well with the results obtained from chromatograph. The results would provide a novel analysis method for the rapid characterization and quantitative determination of the intracellular PHA content in the activated sludge.
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Two-Dimensional Correlation Spectroscopic Analysis on the Interaction between Humic Acids and TiO2 Nanoparticles.
Environ. Sci. Technol.
PUBLISHED: 09-26-2014
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The elucidation of the interaction between TiO2 nanoparticles (NPs) and natural organic matter (NOM) can help one to better understand the fates, features, and environmental impacts of NPs. In this work, two-dimensional (2D) Fourier transformation infrared (FTIR) correlation spectroscopy (CoS) assisted by the fluorescence excitation-emission matrix (EEM) method is used to explore the interaction mechanism of humic acid (HA) with TiO2 NPs at a molecular level. The results show that the C?O bonds (carboxylate, amide, quinone, or ketone) and C-O bonds (phenol, aliphatic C-OH, and polysaccharide) of HA play important roles in their interaction with TiO2 NPs. The adsorption process of HA onto the surface of TiO2 NPs is different from the bonding process of the two species in solution. The forms of the relevant groups of HA and their consequent reaction with TiO2 NPs are affected to a great extent by the solution pH and the surface charge of NPs. The 2D-FTIR-CoS method is found to be able to construct a comprehensive picture about the NOM-TiO2 NPs interaction process. This 2D-FTIR-CoS approach might also be used to probe other complicated interaction processes in natural and engineered environments.
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Light-driven microbial dissimilatory electron transfer to hematite.
Phys Chem Chem Phys
PUBLISHED: 09-20-2014
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The ability of dissimilatory metal-reducing microorganisms (DMRM) to conduct extracellular electron transfer with conductive cellular components grants them great potential for bioenergy and environmental applications. Crystalline Fe(iii) oxide, a type of widespread electron acceptor for DMRM in nature, can be excited by light for photocatalysis and microbial culture-mediated photocurrent production. However, the feasibility of direct electron transfer from living cells to light-excited Fe(iii) oxides has not been well documented and the cellular physiology in this process has not been clarified. To resolve these problems, an electrochemical system composed of Geobacter sulfurreducens and hematite (?-Fe2O3) was constructed, and direct electron transfer from G. sulfurreducens cells to the light-excited ?-Fe2O3 in the absence of soluble electron shuttles was observed. Further studies evidenced the efficient excitation of ?-Fe2O3 and the dependence of photocurrent production on the biocatalytic activity. Light-induced electron transfer on the cell-?-Fe2O3 interface correlated linearly with the rates of microbial respiration and substrate consumption. In addition, the G. sulfurreducens cells were found to survive on light-excited ?-Fe2O3. These results prove a direct mechanism behind the DMRM respiration driven by photo-induced charge separation in semiconductive acceptors and also imply new opportunities to design photo-bioelectronic devices with living cells as a catalyst.
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A Green Approach for Preparing Doped TiO2 Single Crystals.
ACS Appl Mater Interfaces
PUBLISHED: 09-16-2014
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Doped TiO2 with metal, nonmetal, and rare earth elements has shown a great potential in energy and environmental applications, but it is difficult to dope well-defined TiO2 single crystals (SCs) with {001} exposed facet due to their high crystallinity. In this work, we developed a green and general approach to prepare the {001}-exposed TiO2 SCs doped with various elements, on the basis of recycling the wasted ethylene glycol electrolyte from the anodic oxidation for TiO2 nanotube preparation. All six representative elements (i.e., metal, nonmetal, and rare earth types) could be successfully doped into the TiO2 SCs without breaking their single-crystalline structure and exposed high-energy facet. The electronic properties of the doped TiO2 SCs were significantly improved. All the doped TiO2 SCs exhibited a superior photoactivity under visible-light irradiation for degrading rhodamine B, a typical organic pollutant. The prepared doped TiO2 SCs have a promising potential in environmental and energy applications.
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Reduced graphene oxide supported palladium nanoparticles via photoassisted citrate reduction for enhanced electrocatalytic activities.
ACS Appl Mater Interfaces
PUBLISHED: 09-02-2014
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Reduced graphene oxide (rGO) supported palladium nanoparticles (Pd NPs) with a size of ?3 nm were synthesized using one-pot photoassisted citrate reduction. This synthetic approach allows for the formation and assembly of Pd NPs onto the rGO surface with a desired size and can be readily used for other metal NP preparation. The prepared rGO-Pd exhibited 5.2 times higher mass activity for ethanol oxidation reaction than the commercial platinum/carbon (Pt/C). In the oxygen reduction reaction tests, rGO-Pd exhibited comparable activity compared with Pt/C and maintained its high performance after 4000 cycles of potential sweep. These results demonstrate that our synthetic approach is effective for preparing graphene-supported metal NPs with excellent activity and stability in ethanol oxidation and oxygen reduction reactions.
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Investigation on the evolution of N-containing organic compounds during pyrolysis of sewage sludge.
Environ. Sci. Technol.
PUBLISHED: 08-28-2014
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Pyrolysis is an emerging technology for the disposal of huge amounts of sewage sludge. However, the thermochemical decomposition mechanism of organic compounds in sludge is still unclear. We adopt a novel online TG-FTIR-MS technology to investigate the pyrolysis of sludge. The sludge samples were pyrolyzed from 150 to 800 °C with heating rates of 10, 50, and 200 K min(-1). We found for the first time that the heating rate of pyrolysis can significantly change the species of liquid organic compounds produced, but cannot change the gaseous species produced under the same conditions. The contents of produced gas and liquid compounds, most of which were produced at 293-383 °C, are influenced by both the heating rate and temperature of pyrolysis. The results also showed that heterocyclic-N, amine-N, and nitrile-N compounds are obtained from the decomposition of N-compounds in sludge, such as pyrrolic-N, protein-N, amine-N, and pyridinic-N. Heterocyclic-N compounds are the dominant N-containing products, which can be due to the thermochemical decomposition of pyridine-N and pyrrole-N, whereas fewer amine-N compounds are produced during the pyrolysis. A mechanism for the decomposition of N-containing compounds in sludge is proposed based on the obtained data.
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An UV-vis spectroelectrochemical approach for rapid detection of phenazines and exploration of their redox characteristics.
Biosens Bioelectron
PUBLISHED: 08-21-2014
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Phenazines are widely distributed in the environment and play an important role in various biological processes to facilitate microbial metabolism and electron transfer. In this work, an efficient and reliable spectroelectrochemical method is developed to quantitatively detect 1-hydroxyphenazine (1-OHPZ), a representative phenazine, and explore its redox characteristics. This approach is based on the sensitive absorption change of 1-OHPZ in response to its changes under redox state in rapid electrochemical reduction. The redox reaction of 1-OHPZ in aqueous solution is a proton-coupled electron transfer process, with a reversible one-step 2e(-)/2H(+) transfer reaction. This spectroelectrochemical approach exhibits good linear response covering two magnitudes to 1-OHPZ with a detection limit of 0.48µM, and is successfully applied to detect 1-OHPZ from a mixture of phenazines produced by Pseudomonas aeruginosa cultures. This method might also be applicable in exploring the abundance and redox processes of a wide range of other redox-active molecules in natural and engineered environments.
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Quorum quenching is responsible for the underestimated quorum sensing effects in biological wastewater treatment reactors.
Bioresour. Technol.
PUBLISHED: 08-13-2014
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Quorum sensing (QS) and quorum quenching (QQ) are two antagonistic processes coexisting in various bacterial communities in bioreactors, e.g., activated sludge for biological wastewater treatment. Although QS signal molecules are detected in activated sludge reactors and known to affect sludge properties and reactor performance, there has been no direct evidence to prove the endogenous existence of QQ effects in activated sludge. In this study, for the first time, acyl homoserine lactones-degrading enzymatic activity, a typical QQ effect, was discovered in activated sludge and found to considerably affect the QS detection results. The coexistence of QS and QQ bacteria in activated sludge was further confirmed by bacterial screening and denaturing gradient gel electrophoresis analysis. The method developed in this study could also be used to evaluate QQ activities in bioreactors, and a possible way is provided to tune bioreactor performance through balancing the QS and QQ processes.
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Determination of autoinducer-2 in biological samples by high-performance liquid chromatography with fluorescence detection using pre-column derivatization.
J Chromatogr A
PUBLISHED: 08-11-2014
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Autoinducer-2 (AI-2), as a small-molecular-weight organic molecule secreted and perceived by various bacteria, enables intra- and inter-species communications. Quantitative determination of AI-2 is essential for exploring the bacterial AI-2-related physiological and biochemical processes. However, current strategies for sensitive detection of AI-2 require sophisticated instruments and complicated procedures. In this work, on the basis of the derivatization of AI-2 with 2,3-diaminonaphthalene, a simple, sensitive and cost-effective high-performance liquid chromatography with fluorescence detector (HPLC-FLD) method is developed for the quantitative detection of AI-2. Under the optimized conditions, this method had a broad linear range of 10-14,000 ng/ml (R(2)=0.9999), and a low detection limit of 1.0 ng/ml. Furthermore, the effectiveness of this approach was further validated through measuring the AI-2 concentrations in the cell-free culture supernatants of both Escherichia coli and Vibrio harveyi.
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Inhibition of enterovirus 71 by adenosine analog NITD008.
J. Virol.
PUBLISHED: 08-06-2014
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Enterovirus 71 (EV71) is a major viral pathogen in China and Southeast Asia. There is no clinically approved vaccine or antiviral therapy for EV71 infection. NITD008, an adenosine analog, is an inhibitor of flavivirus that blocks viral RNA synthesis. Here we report that NITD008 has potent antiviral activity against EV71. In cell culture, the compound inhibits EV71 at a 50% effective concentration of 0.67 ?M and a 50% cytotoxic concentration of 119.97 ?M. When administered at 5 mg/kg in an EV71 mouse model, the compound reduced viral loads in various organs and completely prevented clinical symptoms and death. To study the antiviral mechanism and drug resistance, we selected escape mutant viruses by culturing EV71 with increasing concentrations of NITD008. Resistance mutations were reproducibly mapped to the viral 3A and 3D polymerase regions. Resistance analysis with recombinant viruses demonstrated that either a 3A or a 3D mutation alone could lead to resistance to NITD008. A combination of both 3A and 3D mutations conferred higher resistance, suggesting a collaborative interplay between the 3A and 3D proteins during viral replication. The resistance results underline the importance of combination therapy required for EV71 treatment. Importance: Human enterovirus 71 (EV71) has emerged as a major cause of viral encephalitis in children worldwide, especially in the Asia-Pacific region. Vaccines and antivirals are urgently needed to prevent and treat EV71 infections. In this study, we report the in vitro and in vivo efficacy of NITD008 (an adenosine analog) as an inhibitor of EV71. The efficacy results validated the potential of nucleoside analogs as antiviral drugs for EV71 infections. Mechanistically, we showed that mutations in the viral 3A and 3D polymerases alone or in combination could confer resistance to NITD008. The resistance results suggest an intrinsic interaction between viral proteins 3A and 3D during replication, as well as the importance of combination therapy for the treatment of EV71 infections.
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Direct three-dimensional characterization and multiscale visualization of wheat straw deconstruction by white rot fungus.
Environ. Sci. Technol.
PUBLISHED: 08-05-2014
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Microbial degradation of lignocellulose for resource and energy recovery has received increasing interest. Despite its obvious importance, the mechanism behind the biodegradation, especially the changes of morphological structure and surface characteristics, has not been fully understood. Here, we used three-dimensional (3D) characterization and multiscale visualization methods, in combination with chemical compositional analyses, to elucidate the degradation process of wheat straw by a white rot fungus, Phanerochaete chrysosporium. It was found that the fungal attack initiated from stomata. Lignin of the straw decayed in both size and quantity, and heterogeneity in the biodegradation was observed. After treatment with the fungus, the straw surface turned from hydrophobic to hydrophilic, and the adhesion of the straw surface increased in the fungal degradation. The morphology of the straw outer layer became heterogeneous and loose with the formation of many holes with various sizes. The wasp-tunnels-like structure of the collenchyma and parenchyma of the straw as well as the fungal hyphae interspersed inside the straw structure were clearly visualized in the 3D reconstruction structure. This work offers a new insight into the mechanism of lignocellulose biodegradation and demonstrates that multiscale visualization methods could be a useful tool to explore such complex processes.
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An MFC-Based Online Monitoring and Alert System for Activated Sludge Process.
Sci Rep
PUBLISHED: 07-14-2014
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In this study, based on a simple, compact and submersible microbial fuel cell (MFC), a novel online monitoring and alert system with self-diagnosis function was established for the activated sludge (AS) process. Such a submersible MFC utilized organic substrates and oxygen in the AS reactor as the electron donor and acceptor respectively, and could provide an evaluation on the status of the AS reactor and thus give a reliable early warning of potential risks. In order to evaluate the reliability and sensitivity of this online monitoring and alert system, a series of tests were conducted to examine the response of this system to various shocks imposed on the AS reactor. The results indicate that this online monitoring and alert system was highly sensitive to the performance variations of the AS reactor. The stability, sensitivity and repeatability of this online system provide feasibility of being incorporated into current control systems of wastewater treatment plants to real-time monitor, diagnose, alert and control the AS process.
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Electrochemical degradation of refractory pollutants using TiO2 single crystals exposed by high-energy {001} facets.
Water Res.
PUBLISHED: 06-16-2014
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Anodic material plays a vital role in electrochemical water treatment. Titanium dioxide (TiO2) has been widely recognized as an excellent semiconductor photocatalyst, rather than an efficient electrocatalyst, due to its relatively low electric conductivity and poor electrochemical activity. In this work, it is found that TiO2 can actually become a superior electrocatalyst when its crystal shape and exposed facet are finely tuned. The shape-engineered TiO2 single crystals with {001} facets exhibit an excellent electro-catalytic activity and stability for degrading typical organic pollutants such as rhodamine B and bisphenol A, and treating complex landfill leachate. Its electro-catalytic superiority is mainly attributed to the single-crystalline structure and exposed polar {001} facet. Our findings could provide new possibility of utilizing TiO2 for efficient electrochemical water treatment because of its high activity, great stability, low cost and no toxicity.
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Characterization of cefalexin degradation capabilities of two Pseudomonas strains isolated from activated sludge.
J. Hazard. Mater.
PUBLISHED: 05-20-2014
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Pharmaceuticals have recently been regarded as contaminants of emerging concern. To date, there is limited knowledge about antibiotic-degrading microorganisms in conventional activated sludge treatment systems and their characteristics toward antibiotic degradation especially in the presence of a pharmaceutical mixture. As such, antibiotic-degrading microorganisms were investigated and isolated from the activated sludge, and their degradation capabilities were evaluated. Two strains of cefalexin-degrading bacteria CE21 and CE22 were isolated and identified as Pseudomonas sp. in the collected activated sludge. Strain CE22 was able to degrade over 90% of cefalexin, while CE21 was able to remove 46.7% of cefalexin after incubation for 24h. The removal efficiency of cefalexin by CE22, different from that of CE21, was not significantly affected by an increase in cefalexin concentration, even up to 10ppm, however the presence of 1ppm of other pharmaceuticals had a significant effect on the degradation of cefalexin by CE22, but no significant effect on CE21. The degradation product of cefalexin by the two strains was identified to be 2-hydroxy-3-phenyl pyrazine. Our results also indicated that CE21 and CE22 were able to degrade caffeine, salicylic acid and chloramphenicol. Moreover, CE21 was found to be capable of eliminating sulfamethoxazole and naproxen.
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Conductive carbon nanotube hydrogel as a bioanode for enhanced microbial electrocatalysis.
ACS Appl Mater Interfaces
PUBLISHED: 05-20-2014
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Enhancing microbial electrocatalysis through new material design is essential to the efficient and stable operation of bio-electrochemical system (BES). In this work, a novel conductive carbon nanotube (CNT) hydrogel was fabricated by electrodepositing both CNT and chitosan onto a carbon paper electrode and used as a BES anode electrode. The microscopic, spectroscopic, and electrochemical analytical results show that the CNT hydrogel exhibited an excellent electrochemical activity. In the BES tests, the current generation and the maximum power density of the MFC with the CNT hydrogel increased by 23% and 65%, respectively, compared with the control. This demonstrates that the utilization of such a hydrogel offers an effective approach to enhance the current generation of BES. The great conductivity of CNT and the high content of oxygen-containing functional groups (C-OH, C?O, etc.) on their surface were found to be responsible for the improvements. Our work provides a facile way to prepare appropriate BES electrodes and offers a straightforward and effective route to enhance the BES performance.
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Synthesis of a highly efficient BiOCl single-crystal nanodisk photocatalyst with exposing {001} facets.
ACS Appl Mater Interfaces
PUBLISHED: 05-09-2014
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BiOCl is known as a highly efficient photocatalyst for degradation of pollutants. However, effective methods for fabricating BiOCl nanomaterials with well-defined facets are still lacking. In this work, a facile synthetic method was developed for the fabrication of BiOCl nanodisks with exposed {001} facets. The central feature of this approach was the use of water as the hydrolysis agent and ethylene glycol as the crystal growth inhibitor agent to tune the growth of BiOCl nanomaterial. With this approach, the size and shape of BiOCl nanostructures could be effectively tuned through adjusting the volume ratio of ethylene glycol/H2O. In addition, the mechanism of the crystal growth in this fabrication process was elucidated. The as-prepared BiOCl nanodisks with exposed {001} facets exhibited an excellent photocatalytic activity towards Rhodamine B degradation under both ultraviolet and visible light irradiations. These findings shed light on the deep understanding of formation mechanisms of BiOCl nanodisks and provide an efficient and facile method for the synthesis of high active photocatalyst.
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The interface between methyltransferase and polymerase of NS5 is essential for flavivirus replication.
PLoS Negl Trop Dis
PUBLISHED: 05-01-2014
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The flavivirus NS5 harbors both a methyltransferase (MTase) and an RNA-dependent RNA polymerase (RdRP). Both enzyme activities of NS5 are critical for viral replication. Recently, the full-length NS5 crystal structure of Japanese encephalitis virus reveals a conserved MTase-RdRP interface that features two conserved components: a six-residue hydrophobic network and a GTR sequence. Here we showed for the first time that these key interface components are essential for flavivirus replication by various reverse genetics approaches. Interestingly, some replication-impaired variants generated a common compensatory NS5 mutation outside the interface (L322F), providing novel routes to further explore the crosstalk between MTase and RdRP.
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Enhancement of nitrogen and phosphorus removal from eutrophic water by economic plant annual ryegrass (Lolium multiflorum) with ion implantation.
Environ Sci Pollut Res Int
PUBLISHED: 04-30-2014
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Severe eutrophication of surface water has been a major problem of increasing environmental concern worldwide. In the present study, economic plant annual ryegrass (Lolium multiflorum) was grown in floating mats as an economic plant-based treatment system to evaluate its potential after ion implantation for removing nutrients in simulated eutrophic water. The specific weight growth rate of L. multiflorum with ion implantation was significantly greater than that of the control, and the peroxidase, nitrate reductase, and acid phosphatase activities of the irradiated L. multiflorum were found to be greater than those plants without ion implantation. Higher total nitrogen (TN) and total phosphorus (TP) removal efficiencies were obtained for the L. multiflorum irradiated with 25 keV 5.2?×?10(16) N(+) ions/cm(2) and 30 keV 4.16?×?10(16) N(+) ions/cm(2), respectively (p?
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Comprehensive analysis of Sichuan white geese (Anser cygnoides) transcriptome.
Anim. Sci. J.
PUBLISHED: 04-13-2014
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High-throughput RNA sequencing was performed for comprehensively analyzing the transcriptome of geese. A total of 28,803,759 bp of raw sequence data was generated by 454 GS Flx+. After removal of adaptor sequences, 28,730,361 bp remained and 117,279 reads were obtained, with an average length of 244 bases. Simultaneously, complementary DNA samples from two different reproductive stages of goose ovarian, hypothalamus and pituitary tissue were sequenced separately using Illumina MiSeq platform. A total of 12?688?673?148 bp of raw sequence data were generated by Illumina MiSeq. After removal of adaptor sequences, 8?198?126?562 bp remained and 60?382?786 clean reads were obtained, with an average length of 135 bases. Assembly of all the reads from both 454 Flx+ and Illumina platforms formed 56,839 contigs. The sequence size ranges from 38 to 28,206 bp in size, with an average size of 2584 bp and an N50 of 4624. The assembly produced a substantial number of large contigs: 35,545 (62.5%) were longer than 1?kb, of which 8850 (15.6%) were longer than 5?kb. The sequencing depth was 85 X on average. We performed comprehensive function annotations on unigenes including protein sequence similarity, gene ontology (GO) term classification, and Kyoto Encylcopedia of Genes and Genomes (KEGG) pathway enrichment. GO analysis showed that approximately 63% of the contigs had annotation information, among the 35,953 annotated isotigs in Nr database, 24,783 (68.9%) sequences were assigned with one or more GO terms. There were 14,634 (40.7%) isotigs for biological processes, 10,557(29.3%) isotigs for cellular component, 22,607 (62.9%) isotigs for molecular function. The result of KEGG pathway mapping 8926 sequences had the pathway annotation, and took part in 477 pathways. Additionally, 10,685 simple sequence repeat (SSR) markers were identified from the assembled sequences. The most frequent repeat motifs were trinucleotides, which accounted for 53.03% of all SSRs, followed by dinucleotides (39.9%), tetranucleotides (5.08%), pentanucleotides (1.68%) and hexanucleotides (0.32%). Transcriptome sequencing on mixture issue of the geese yielded substantial transcriptional sequences and potentially useful SSR markers which provide an important data source for geese research.
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Molecular control of arsenite-induced apoptosis in Caenorhabditis elegans: roles of insulin-like growth factor-1 signaling pathway.
Chemosphere
PUBLISHED: 04-02-2014
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Apoptosis is one of the main cellular processes in responses to arsenic, the well known environmental carcinogen. By using the nematode Caenorhabditis elegans as an in vivo model, we found that insulin-like growth factor-1 networks and their target protein DAF-16/FOXO, known as key regulators of energy metabolism and growth, played important roles in arsenite-induced apoptosis. Inactivation of DAF-2, AGE-1 and AKT-1 caused worms more susceptible to arsenite-induced apoptosis, which could be attenuated by DAF-16 knockout. Worms with inactivated AKT-2 and SGK-1 or with constitutively activated PDK-1 and AKT-1 showed low levels of apoptosis, which could be elevated by DAF-16 mutation. Our results demonstrated that DAF-2/IGF-1R, AGE-1/PI3K, PDK-1/PDK1 and AKT-1/PKB negatively regulated the arsenite-induced apoptosis, whereas AKT-2 and SGK-1 acted proapoptotically. DAF-16/FOXO antagonized IGF-1 signals in signaling the arsenite-induced apoptosis, and apoptosis promoted by DAF-16 inactivation was attributed to its higher sensitivity to oxidative stress.
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The maximum specific hydrogen-producing activity of anaerobic mixed cultures: definition and determination.
Sci Rep
PUBLISHED: 03-10-2014
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Fermentative hydrogen production from wastes has many advantages compared to various chemical methods. Methodology for characterizing the hydrogen-producing activity of anaerobic mixed cultures is essential for monitoring reactor operation in fermentative hydrogen production, however there is lack of such kind of standardized methodologies. In the present study, a new index, i.e., the maximum specific hydrogen-producing activity (SHAm) of anaerobic mixed cultures, was proposed, and consequently a reliable and simple method, named SHAm test, was developed to determine it. Furthermore, the influences of various parameters on the SHAm value determination of anaerobic mixed cultures were evaluated. Additionally, this SHAm assay was tested for different types of substrates and bacterial inocula. Our results demonstrate that this novel SHAm assay was a rapid, accurate and simple methodology for determining the hydrogen-producing activity of anaerobic mixed cultures. Thus, application of this approach is beneficial to establishing a stable anaerobic hydrogen-producing system.
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Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.
Appl. Biochem. Biotechnol.
PUBLISHED: 03-10-2014
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In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source.
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Experimental and Theoretical Approaches for the Surface Interaction between Copper and Activated Sludge Microorganisms at Molecular Scale.
Sci Rep
PUBLISHED: 02-28-2014
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Interactions between metals and activated sludge microorganisms substantially affect the speciation, immobilization, transport, and bioavailability of trace heavy metals in biological wastewater treatment plants. In this study, the interaction of Cu(II), a typical heavy metal, onto activated sludge microorganisms was studied in-depth using a multi-technique approach. The complexing structure of Cu(II) on microbial surface was revealed by X-ray absorption fine structure (XAFS) and electron paramagnetic resonance (EPR) analysis. EPR spectra indicated that Cu(II) was held in inner-sphere surface complexes of octahedral coordination with tetragonal distortion of axial elongation. XAFS analysis further suggested that the surface complexation between Cu(II) and microbial cells was the distorted inner-sphere coordinated octahedra containing four short equatorial bonds and two elongated axial bonds. To further validate the results obtained from the XAFS and EPR analysis, density functional theory calculations were carried out to explore the structural geometry of the Cu complexes. These results are useful to better understand the speciation, immobilization, transport, and bioavailability of metals in biological wastewater treatment plants.
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Glutathione S-transferase A1 (GSTA1) release, an early indicator of acute hepatic injury in mice.
Food Chem. Toxicol.
PUBLISHED: 02-24-2014
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Three acute hepatic injury models (a CCl4-induced model, APAP-induced model and ethanol-induced model) in mice were used to study the importance of GSTA1 in acute hepatic injury by comparison with a standard enzyme marker, alanine aminotransferase (ALT). GSTA1 release was demonstrated to be an earlier and more sensitive indicator of hepatotoxicity than was ALT. Significant increases in GSTA1 were detected at 2 h after CCl4 exposure, while ALT was undetected at this time. GSTA1 was also a more sensitive indicator of hepatotoxicity than ALT after 6 h. In the APAP and ethanol models, GSTA1 was markedly increased earlier than ALT, at 2 h post exposure. The release of GSTA1 was significantly increased at a dose of 12.5 mg/kg (CCl4 model), 100 mg/kg (APAP model) and 10 ml/kg (ethanol model), the lowest exposure concentration for each model. In contrast, AST release was not statistically significant. These results suggest that GSTA1 can be detected at low concentrations during the early stages of acute hepatic injury and that GSTA1 is a more sensitive and more accurate indicator than ALT.
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Platelets induce a proinflammatory phenotype in monocytes via the CD147 pathway in rheumatoid arthritis.
Arthritis Res. Ther.
PUBLISHED: 02-19-2014
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IntroductionActivated platelets exert a proinflammatory action that can be largely ascribed to their ability to interact with monocytes. However, the mechanisms that promote dynamic changes in monocyte subsets in rheumatoid arthritis (RA) have not been clearly identified. The aim of this study was to determine whether platelet activation and the consequent formation of monocyte-platelet aggregates (MPA) might induce a proinflammatory phenotype in circulating monocytes in RA.MethodsThe surface phenotype of platelets and the frequencies of monocyte subpopulations in the peripheral blood of RA patients were determined using flow cytometry. Platelets were sorted and co-cultured with monocytes. In addition, monocyte activation was assessed by measuring the nuclear factor ¿B (NF-¿B) pathway. The disease activity was evaluated using the 28-joint disease activity score.ResultsPlatelet activation, circulating intermediate monocytes (Mon2) and MPA formation were significantly elevated in RA, especially in those with active disease status. Furthermore, Mon2 monocytes showed higher CD147 expression and responded to direct cell contact with activated platelets with higher cytokine production and matrix metallopeptidase 9 (MMP-9) secretion, which increased the expression of CD147. After the addition of specific antibodies for CD147, those effects were abolished. Furthermore, the NF-¿B¿driven inflammatory pathway may be involved in this process.ConclusionThese findings indicate an important role of platelet activation and the consequent formation of MPA in the generation of the proinflammatory cytokine milieu and for the promotion and maintenance of the pathogenically relevant Mon2 monocyte compartment in RA, which is likely to play an important role in the pathogenesis of autoimmunity.
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Biological and chemical phosphorus solubilization from pyrolytical biochar in aqueous solution.
Chemosphere
PUBLISHED: 02-18-2014
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Biochar, a massive byproduct of biomass pyrolysis during biofuel generation, is a potential P source for the mitigation of P depletion. However, the chemical and biological effect of the release of P from biochar is still unclear. In this study, two types of Lysinibacillus strains (Lysinibacillussphaericus D-8 and Lysinibacillus fusiformis A-5) were separated from a sediment and their P-solubilizing characteristics to biochar was first reported. Compared with the bacterial mixture W-1 obtained from a bioreactor, the introduction of A-5 and D-8 significantly improved P solubilization. The release of P from biochar by A-5 and D-8 reached 54% and 47%, respectively, which is comparable to that under rigorous chemical conditions. SEM images and XPS spectra demonstrated that the physicochemical properties of the biochar surface have changed in the process which may be caused by the activities of the microbes.
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miR-335 represents an independent prognostic marker in epithelial ovarian cancer.
Am. J. Clin. Pathol.
PUBLISHED: 02-12-2014
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To investigate the clinical significance of miR-335 expression in epithelial ovarian cancer (EOC).
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The protective effect of vanadium against diabetic cataracts in diabetic rat model.
Biol Trace Elem Res
PUBLISHED: 01-25-2014
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The present study was designed to investigate the effect of vanadium in alloxan-induced diabetes and cataract in rats. Different doses of vanadium was administered once daily for 8 weeks to alloxan-induced diabetic rats. To know the mechanism of action of vanadium, lens malondialdehyde (MDA), protein carbonyl content, activity of superoxide dismutase (SOD), activities of aldose reductase (AR), and sorbitol levels were assayed, respectively. Supplementation of vanadium to alloxan-induced diabetic rats decreased the blood glucose levels due to hyperglycemia, inhibited the AR activity, and delayed cataract progression in a dose-dependent manner. The observed beneficial effects may be attributed to polyol pathway activation but not decreased oxidative stress. Overall, the results of this study demonstrate that vanadium could effectively reduce the alloxan-induced hyperglycemia and diabetic cataracts in rats.
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Fe?O?@rGO doped molecularly imprinted polymer membrane based on magnetic field directed self-assembly for the determination of amaranth.
Talanta
PUBLISHED: 01-24-2014
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Based on magnetic field directed self-assembly (MDSA) of Fe3O4@rGO composites, a novel magnetic molecularly imprinted electrochemical sensor (MIES) was fabricated and developed for the determination of the azo dye amaranth. Fe3O4@rGO composites were obtained by a one-step approach involving the initial intercalating of iron ions between the graphene oxide layers via the electrostatic interaction, followed by the reduction with hydrazine hydrate to deposit Fe3O4 nanoparticles onto the reduced oxide graphene nanosheets. In molecular imprinting, the complex including the function monomer of aniline, the template of amaranth and Fe3O4@rGO was pre-assembled through ?-? stacking and hydrogen bonding interactions, and then was self-assembled on the surface of magnetic glassy carbon electrode (MGCE) with the help of magnetic field induction before electropolymerization. The structures and morphologies of Fe3O4@rGO and the doped molecularly imprinted polymers (MIPs) were investigated by Fourier transform infrared spectrometer (FT-IR), Raman spectra and scanning electron microscope (SEM). Besides, the characterization by differential pulse voltammetry (DPV) showed that Fe3O4@rGO composites promoted the electrical conductivity of the imprinted sensors when doped into the MIPs. The adsorption isotherms and adsorption kinetics were employed to evaluate the performances of MIES. The detection of amaranth was achieved via the redox probe K3[Fe(CN)6] by blocking the imprinted cavities, which avoided the interferences of oxidation products and analogs of amaranth. Furthermore, the prepared MIES exhibited good sensitivity, selectivity, reproducibility and efficiency for detecting amaranth in fruit drinks. The average recoveries were 93.15-100.81% with the RSD <3.0%.
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Redox reaction characteristics of riboflavin: a fluorescence spectroelectrochemical analysis and density functional theory calculation.
Bioelectrochemistry
PUBLISHED: 01-22-2014
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Riboflavin (RF), the primary redox active component of flavin, is involved in many redox processes in biogeochemical systems. Despite of its wide distribution and important roles in environmental remediation, its redox behaviors and reaction mechanisms in hydrophobic sites remain unclear yet. In this study, spectroelectrochemical analysis and density functional theory (DFT) calculation were integrated to explore the redox behaviors of RF in dimethyl sulfoxide (DMSO), which was used to create a hydrophobic environment. Specifically, cyclic voltafluorometry (CVF) and derivative cyclic voltafluorometry (DCVF) were employed to track the RF concentration changing profiles. It was found that the reduction contained a series of proton-coupled electron transfers dependent of potential driving force. In addition to the electron transfer-chemical reaction-electron transfer process, a disproportionation (DISP1) process was also identified to be involved in the reduction. The redox potential and free energy of each step obtained from the DFT calculations further confirmed the mechanisms proposed based on the experimental results. The combination of experimental and theoretical approaches yields a deep insight into the characteristics of RF in environmental remediation and better understanding about the proton-coupled electron transfer mechanisms.
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Optimizing municipal wastewater treatment plants using an improved multi-objective optimization method.
Bioresour. Technol.
PUBLISHED: 01-20-2014
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An improved multi-objective optimization (MOO) model was established and used for simultaneously optimizing the treatment cost and multiple effluent quality indexes (including effluent COD, NH4(+)-N, NO3(-)-N) of a municipal wastewater treatment plant (WWTP). Compared with previous models that were mainly based on the use of fixed decision factors and did not taken into account the treatment cost, this model introduces a relationship model based on back propagation algorithm to determine the set of decision factors according to the expected optimization targets. Thus, a more flexible and precise optimization of the treatment process was allowed. Moreover, a MOO of conflicting objectives (i.e., treatment cost and effluent quality) was achieved. Applying this method, an optimal balance between operating cost and effluent quality of a WWTP can be found. This model may offer a useful tool for optimized design and control of practical WWTPs.
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Cultivation of aerobic granules for polyhydroxybutyrate production from wastewater.
Bioresour. Technol.
PUBLISHED: 01-19-2014
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Polyhydroxybutyrate (PHB)-rich aerobic granule was cultivated in a sequencing batch reactor (SBR) under nitrogen deficient conditions by adapting a two-step strategy. In the first step the PHB-storage ability of activated sludge was enhanced by keeping both oxygen and ammonia at a low level. In the second step granular sludge was cultivated through adjusting sludge settling time. The matured PHB-rich granular sludge with a PHB content of 40 ± 4.6% and a high settling ability was successfully obtained. The analysis on sludge surface properties showed that the surface charge, extracellular polymeric substances (EPS) content and the sludge hydrophobicity all increased significantly, while the surface energy of sludge decreased to a relatively steady state accompanied with the growth of granular sludge. This study demonstrates that the metabolism of intracellular storages induced microbial production of EPS, which favored the formation of aerobic granules.
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Selenite reduction by Shewanella oneidensis MR-1 is mediated by fumarate reductase in periplasm.
Sci Rep
PUBLISHED: 01-18-2014
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In situ reduction of selenite to elemental selenium (Se(0)), by microorganisms in sediments and soils is an important process and greatly affects the environmental distribution and the biological effects of selenium. However, the mechanism behind such a biological process remains unrevealed yet. Here we use Shewanella oneidensis MR-1, a widely-distributed dissimilatory metal-reducing bacterium with a powerful and diverse respiration capability, to evaluate the involvement of anaerobic respiration system in the microbial selenite reduction. With mutants analysis, we identify fumarate reductase FccA as the terminal reductase of selenite in periplasm. Moreover, we find that such a reduction is dependent on central respiration c-type cytochrome CymA. In contrast, nitrate reductase, nitrite reductase, and the Mtr electron transfer pathway do not work as selenite reductases. These findings reveal a previously unrecognized role of anaerobic respiration reductases of S. oneidensis MR-1 in selenite reduction and geochemical cycles of selenium in sediments and soils.
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Experimental and theoretical demonstrations for the mechanism behind enhanced microbial electron transfer by CNT network.
Sci Rep
PUBLISHED: 01-17-2014
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Bioelectrochemical systems (BESs) share the principle of the microbially catalyzed anodic substrate oxidation. Creating an electrode interface to promote extracellular electron transfer from microbes to electrode and understanding such mechanisms are crucial for engineering BESs. In this study, significantly promoted electron transfer and a 10-times increase in current generation in a BES were achieved by the utilization of carbon nanotube (CNT) network, compared with carbon paper. The mechanisms for the enhanced current generation with the CNT network were elucidated with both experimental approach and molecular dynamic simulations. The fabricated CNT network was found to be able to substantially enhance the interaction between the c-type cytochromes and solid electron acceptor, indicating that the direct electron transfer from outer-membrane decaheme c-type cytochromes to electrode might occur. The results obtained in this study will benefit for the optimized design of new materials to target the outer membrane proteins for enhanced electron exchanges.
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Development of an energy-saving anaerobic hybrid membrane bioreactors for 2-chlorophenol-contained wastewater treatment.
Chemosphere
PUBLISHED: 01-16-2014
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A novel energy-saving anaerobic hybrid membrane bioreactor (AnHMBR) with mesh filter, which takes advantage of anaerobic membrane bioreactor and fixed-bed biofilm reactor, is developed for low-strength 2-chlorophenol (2-CP)-contained wastewater treatment. In this system, the anaerobic membrane bioreactor is stuffed with granular activated carbon to construct an anaerobic hybrid fixed-bed biofilm membrane bioreactor. The effluent turbidity from the AnHMBR system was low during most of the operation period, and the chemical oxygen demand and 2-CP removal efficiencies averaged 82.3% and 92.6%, respectively. Furthermore, a low membrane fouling rate was achieved during the operation. During the AnHMBR operation, the only energy consumption was for feed pump. And a low energy demand of 0.0045-0.0063kWhm(-3) was estimated under the current operation conditions. All these results demonstrated that this novel AnHMBR is a sustainable technology for treating 2-CP-contained wastewater.
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Novel electrochemical sensing platform based on magnetic field-induced self-assembly of Fe3O4@Polyaniline nanoparticles for clinical detection of creatinine.
Biosens Bioelectron
PUBLISHED: 01-03-2014
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A novel electrochemical sensing platform based on magnetic field-induced self-assembly of Fe3O4@Polyaniline nanoparticles (Fe3O4@PANI NPs) has been for the first time fabricated for the sensitive detection of creatinine in biological fluids. The template molecule, creatinine, was self-assembled on the surface of Fe3O4@PANI NPs together with the functional monomer aniline by the formation of N-H hydrogen bonds. After pre-assembled, through the magnetic-induction of the magnetic glassy carbon electrode (MGCE), the ordered structure of molecularly imprinted polymers (MIPs) were established by the electropolymerization and assembled on the surface of MGCE with the help of magnetic fields by a simple one-step approach. The structural controllability of the MIPs film established by magnetic field-induced self-assembly was further studied. The stable and hydrophilic Fe3O4@PANI can not only provide available functionalized sites with which the template molecule creatinine can form hydrogen bond by the abundant amino groups in PANI matrix, but also afford a promoting pathway for electron transfer. The as-prepared molecularly imprinted electrochemical sensor (MIES) shows good stability and reproducibility for the determination of creatinine with the detection limit reached 0.35 nmol L(-1) (S/N=3). In addition, the highly sensitive and selective MIES has been successfully used for the clinical determination of creatinine in human plasma and urine samples. The average recoveries were 90.8-104.9% with RSD lower than 2.7%.
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Biosorption of Cr (VI) by Typha angustifolia: mechanism and responses to heavy metal stress.
Bioresour. Technol.
PUBLISHED: 01-03-2014
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In this study, Typha angustifolia was proven to have an excellent accumulation ability in high concentrations of wastewater solutions having Cr (VI) concentrations up to 30 mg L(-1) for 20 days (74% of removal efficiency). Synchrotron microfocus micro X-ray fluorescence (?-XRF) mapping showed that the uptaken Cr was mainly enriched in the outer layer of the roots and a small portion of it was uniformly distributed in the fronds. The total proteins, soluble sugars, and malondialdehyde in T. angustifolia increased when the concentration of Cr (VI) increased from 9 to 30 mg L(-1). Transmission electron microscope (TEM) assay showed that no lignifications were observed when Cr was absorbed by T. angustifolia. It was concluded that T. angustifolia can uptake Cr by means of surface layer absorption and transportation, and alleviate stresses associated with the sorption of Cr (VI) by thickening of cell walls or secretion of chemical substances.
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HAb18G/CD147 regulates vinculin-mediated focal adhesion and cytoskeleton organization in cultured human hepatocellular carcinoma cells.
PLoS ONE
PUBLISHED: 01-01-2014
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Focal adhesions (FAs), integrin-mediated macromolecular complexes located at the cell membrane extracellular interface, have been shown to regulate cell adhesion and migration. Our previous studies have indicated that HAb18G/CD147 (CD147) is involved in cytoskeleton reorganization and FA formation in human hepatocellular carcinoma (HCC) cells. However, the precise mechanisms underlying these processes remain unclear. In the current study, we determined that CD147 was involved in vinculin-mediated FA focal adhesion formation in HCC cells. We also found that deletion of CD147 led to reduced vinculin-mediated FA areas (P<0.0001), length/width ratios (P<0.0001), and mean intensities (P<0.0001). CD147 promoted lamellipodia formation by localizing Arp2/3 to the leading edge of the cell. Deletion of CD147 significantly reduced the fluorescence (t1/2) recovery times (22.7±3.3 s) of vinculin-mediated focal adhesions (P<0.0001). In cell-spreading assays, CD147 was found to be essential for dynamic focal adhesion enlargement and disassembly. Furthermore, the current data showed that CD147 reduced tyrosine phosphorylation in vinculin-mediated focal adhesions, and enhanced the accumulation of the acidic phospholipid phosphatidylinositol-4, 5-bisphosphate (PIP2). Together, these results revealed that CD147 is involved in vinculin-mediated focal adhesion formation, which subsequently promotes cytoskeleton reorganization to facilitate invasion and migration of human HCC cells.
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Recovery of a chemically synthesized Japanese encephalitis virus revealed two critical adaptive mutations in NS2B and NS4A.
J. Gen. Virol.
PUBLISHED: 12-20-2013
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Full-length genome infectious clone is a powerful tool for functional assay in virology. In this study, using a chemical synthesized complete genome of Japanese encephalitis virus (JEV) strain SA14 (GenBank No. U14163), we constructed a full-length genomic cDNA clone of JEV. The recovered viruses from the cDNA clone replicated poorly in either BHK-21 cells or in suckling mice brain. Following serial passage in BHK-21 cells, adaptive mutations within NS2B and NS4A were recovered in the passaged viruses leading to viruses with large plaque phenotype. Mutagenesis analysis, using a genome-length RNA and a replicon of JEV, demonstrated that the adaptive mutations restored replication to different degrees, and the restoration efficiencies were on the order of NS2B-T102M
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A plate-based electrochromic approach for the high-throughput detection of electrochemically active bacteria.
Nat Protoc
PUBLISHED: 12-19-2013
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Electrochemically active bacteria (EAB) have the ability to transfer electrons to electron acceptors located outside the cell, and they are widely present in diverse environments. In spite of their important roles in geochemical cycles, environmental remediation and electricity generation, so far, only a limited number and types of EAB have been isolated and characterized. Thus, effective and rapid EAB identification methods are highly desirable. In this protocol, we describe a photometric protocol for the visualization and high-throughput identification and isolation of EAB. The protocol relies on the fast electron acquisition and color change ability of an electrochromic material, namely a tungsten trioxide (WO3) nanorod assembly. The extracellular electron transfer (EET) from EAB to the WO3 nanorod assembly probe is accompanied by a bioelectrochromic reaction made evident by the color change of the probe. This protocol enables researchers to rapidly identify EAB and evaluate their EET ability either qualitatively with the naked eye or quantitatively by image analysis. We have also successfully used this protocol to isolate EAB from environmental samples. The time needed to complete this protocol is ?2 d, with the actual EAB identification process taking about 5 min.
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Insight into the roles of microbial extracellular polymer substances in metal biosorption.
Bioresour. Technol.
PUBLISHED: 10-02-2013
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Biosorption presents a potent technology to remediate metal-contaminated aqueous environment or even to recover precious metals. Extracellular polymeric substances (EPS) are believed to play an important role in metal biosorption by microorganisms, but the reported results have been rather contradictory and the underlying mechanisms remain largely unclear so far. This review aims to clarify why large discrepancies existed for different EPS-metal systems through systematically exploring into the adsorption mechanisms and influential factors, and to offer some implications for advancing the implementation of metal biosorption technologies. The state-of-the-art methodologies for characterizing metal-EPS binding are summarized; several interaction mechanisms, including ion exchange, complexation and surface precipitation, are analyzed; the major influential factors such as EPS composition, metal species, solution chemistry and operating conditions are discussed; and lastly future research needs to advance the investigations and implementations of such biosorption processes are proposed.
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Phosphorus removal in an enhanced biological phosphorus removal process: roles of extracellular polymeric substances.
Environ. Sci. Technol.
PUBLISHED: 09-25-2013
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Phosphorus-accumulating organisms are considered to be the key microorganisms in the enhanced biological phosphorus removal (EBPR) process. A large amount of phosphorus is found in the extracellular polymeric substances (EPS) matrix of these microorganisms. However, the roles of EPS in phosphorus removal have not been fully understood. In this study, the phosphorus in the EBPR sludge was fractionated and further analyzed using quantitative (31)P nuclear magnetic resonance spectroscopy. The amounts and forms of phosphorus in EPS as well as their changes in an anaerobic-aerobic process were also investigated. EPS could act as a reservoir for phosphorus in the anaerobic-aerobic process. About 5-9% of phosphorus in sludge was reserved in the EPS at the end of the aerobic phase and might further contribute to the phosphorus removal. The chain length of the intracellular long-chain polyphosphate (polyP) decreased in the anaerobic phase and then recovered under aerobic conditions. However, the polyP in the EPS had a much shorter chain length than the intracellular polyP in the whole cycle. The migration and transformation of various forms of phosphorus among microbial cells, EPS, and bulk liquid were also explored. On the basis of these results, a model with a consideration of the roles of EPS was proposed, which is beneficial to elucidate the mechanism of phosphorus removal in the EBPR system.
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Mesoporous carbon stabilized MgO nanoparticles synthesized by pyrolysis of MgCl2 preloaded waste biomass for highly efficient CO2 capture.
Environ. Sci. Technol.
PUBLISHED: 08-12-2013
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Anthropogenic CO2 emission makes significant contribution to global climate change and CO2 capture and storage is a currently a preferred technology to change the trajectory toward irreversible global warming. In this work, we reported a new strategy that the inexhaustible MgCl2 in seawater and the abundantly available biomass waste can be utilized to prepare mesoporous carbon stabilized MgO nanoparticles (mPC-MgO) for CO2 capture. The mPC-MgO showed excellent performance in the CO2 capture process with the maximum capacity of 5.45 mol kg(-1), much higher than many other MgO based CO2 trappers. The CO2 capture capacity of the mPC-MgO material kept almost unchanged in 19-run cyclic reuse, and can be regenerated at low temperature. The mechanism for the CO2 capture by the mPC-MgO was investigated by FTIR and XPS, and the results indicated that the high CO2 capture capacity and the favorable selectivity of the as-prepared materials were mainly attributed to their special structure (i.e., surface area, functional groups, and the MgO NPs). This work would open up a new pathway to slow down global warming as well as resolve the pollution of waste biomass.
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Later passages of neural progenitor cells from neonatal brain are more permissive for human cytomegalovirus infection.
J. Virol.
PUBLISHED: 07-31-2013
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Congenital human cytomegalovirus (HCMV) infection is the most frequent infectious cause of birth defects, primarily neurological disorders. Neural progenitor/stem cells (NPCs) are the major cell type in the subventricular zone and are susceptible to HCMV infection. In culture, the differentiation status of NPCs may change with passage, which in turn may alter susceptibility to virus infection. Previously, only early-passage (i.e., prior to passage 9) NPCs were studied and shown to be permissive to HCMV infection. In this study, NPC cultures derived at different gestational ages were evaluated after short (passages 3 to 6) and extended (passages 11 to 20) in vitro passages for biological and virological parameters (i.e., cell morphology, expression of NPC markers and HCMV receptors, viral entry efficiency, viral gene expression, virus-induced cytopathic effect, and release of infectious progeny). These parameters were not significantly influenced by the gestational age of the source tissues. However, extended-passage cultures showed evidence of initiation of differentiation, increased viral entry, and more efficient production of infectious progeny. These results confirm that NPCs are fully permissive for HCMV infection and that extended-passage NPCs initiate differentiation and are more permissive for HCMV infection. Later-passage NPCs being differentiated and more permissive for HCMV infection suggest that HCMV infection in fetal brain may cause more neural cell loss and give rise to severe neurological disabilities with advancing brain development.
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Determination of chlorinated hydrocarbons in water using highly sensitive mid-infrared sensor technology.
Sci Rep
PUBLISHED: 06-14-2013
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Chlorinated aliphatic hydrocarbons and chlorinated aromatic hydrocarbons (CHCs) are toxic and carcinogenic contaminants commonly found in environmental samples, and efficient online detection of these contaminants is still challenging at the present stage. Here, we report an advanced Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) sensor for in-situ and simultaneous detection of multiple CHCs, including monochlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, trichloroethylene, perchloroethylene, and chloroform. The polycrystalline silver halide sensor fiber had a unique integrated planar-cylindric geometry, and was coated with an ethylene/propylene copolymer membrane to act as a solid phase extractor, which greatly amplified the analytical signal and contributed to a higher detection sensitivity compared to the previously reported sensors. This system exhibited a high detection sensitivity towards the CHCs mixture at a wide concentration range of 5~700?ppb. The FTIR-ATR sensor described in this study has a high potential to be utilized as a trace-sensitive on-line device for water contamination monitoring.
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Hexagonal microrods of anatase tetragonal TiO2: self-directed growth and superior photocatalytic performance.
Chem. Commun. (Camb.)
PUBLISHED: 06-04-2013
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Novel TiO2 mesocrystalline microrods with unique hexagonal structure were prepared via a facial thermal method. Their photocatalytic performance under UV irradiation was much higher than that of the Degussa P25 benchmark, one of the best commercial polycrystalline TiO2 photocatalyst. The hexagonal microrods were formed through self-directed self-assembly within intermediate scaffolds.
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Purification and characterization of a laccase from Coprinopsis cinerea in Pichia pastoris.
World J. Microbiol. Biotechnol.
PUBLISHED: 05-24-2013
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A modified laccase gene, CcLCC6, from Coprinopsis cinerea was chemically synthesized according to the yeast codon bias and expressed in Pichia pastoris. The main properties of laccase, effects of ions and inhibitors, and optimal condition for decolouring malachite green (MG) were investigated in this study. The optimal pH level and temperature of laccase are 3.0 and 40 °C, respectively. The metal ions Mn(2+), Zn(2+), Fe(3+) and Al(3+) could inhibit laccase activity, as well as 1 mM of sodium dodecyl sulphate and sodium thiosulphate. 2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), as a mediator, was necessary in decolorizing MG. The optimal pH and temperature for MG decolorization were 3.0 and 50 °C, respectively. Approximately 0.02 ?M recombinant laccase could effectively decolour 0.05 mM of MG in 1 h. CcLCC6I could inhibit the toxicity of MG to P. pastoris. This is the first report on the successful expression in P. pastoris of CcLCC6I and its enzymatic property. Laccase can also be considered as a candidate for treating industrial effluent containing MG.
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Oxygen promotes biofilm formation of Shewanella putrefaciens CN32 through a diguanylate cyclase and an adhesin.
Sci Rep
PUBLISHED: 05-20-2013
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Although oxygen has been reported to regulate biofilm formation by several Shewanella species, the exact regulatory mechanism mostly remains unclear. Here, we identify a direct oxygen-sensing diguanylate cyclase (DosD) and reveal its regulatory role in biofilm formation by Shewanella putrefaciens CN32 under aerobic conditions. In vitro and in vivo analyses revealed that the activity of DosD culminates to synthesis of cyclic diguanylate (c-di-GMP) in the presence of oxygen. DosD regulates the transcription of bpfA operon which encodes seven proteins including a large repetitive adhesin BpfA and its cognate type I secretion system (TISS). Regulation of DosD in aerobic biofilms is heavily dependent on an adhesin BpfA and the TISS. This study offers an insight into the molecular mechanism of oxygen-stimulated biofilm formation by S. putrefaciens CN32.
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Quantification of the interactions between Ca²?, Hg²? and extracellular polymeric substances (EPS) of sludge.
Chemosphere
PUBLISHED: 05-02-2013
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The interactions between metals (Ca(2+) and Hg(2+)) and extracellular polymeric substances (EPS) extracted from the aerobic and anaerobic sludge in wastewater treatment reactors were investigated using a combination of zeta potential measurement and 3-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor (PARAFAC) analysis. Results show that Ca(2+) had no substantial effects on the EEM fluorescence spectra of the EPS, but their zeta potentials increased with the increasing Ca(2+) dosage. However, Hg(2+) had a significant effect on the EEM fluorescence spectra of the EPS, while their zeta potentials seemed not to be affected by the dose of Hg(2+). The interactions between Hg(2+) and EPS were elucidated using the fluorescence quenching with PARAFAC analysis, while the interactions between Ca(2+) and EPS were evaluated by the zeta potential technique. The binding constants for Hg(2+) and EPS were two orders of magnitude higher than those for Ca(2+) and EPS, suggesting that the binding mechanisms between Ca(2+) and EPS were different from those between Hg(2+) and EPS. The results might be useful for understanding the roles of EPS in bacterial self-protection against heavy metals and the aggregate formation mechanisms through ionic bridging interactions.
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Natural antisense transcripts of UL123 packaged in human cytomegalovirus virions.
Arch. Virol.
PUBLISHED: 05-01-2013
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In this study, we demonstrated that antisense transcripts of human cytomegalovirus (HCMV) UL123, UL21.5 and cellular GAPDH genes were present in highly purified virions. These virion RNAs were delivered into the host cells upon infection, and de novo synthesized ones appeared in the infected cell at the immediate early stage. Although the sequence of UL123 antisense transcripts in virions is uncertain, we found that these transcripts in Towne-infected human fibroblasts had novel transcriptional start sites (TSSs) with various 5-terminal deletions of open reading frame (ORF) 59. These findings not only provide new insight into the composition of HCMV virions but also reveal a possible viral strategy for initiating latent infection and switching between latent and productive infections.
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Coagulation kinetics of humic aggregates in mono- and di-valent electrolyte solutions.
Environ. Sci. Technol.
PUBLISHED: 05-01-2013
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Coagulation behaviors of humic acids (HAs) aggregates in electrolyte solutions at different pHs, valences and concentrations of electrolyte cations were investigated using dynamic light scattering technique in combination of other analytical tools. For monovalent electrolyte sodium chloride (NaCl) solution, at its low concentrations the average hydrodynamic radius () of aggregates kept nearly constant. However, at high NaCl concentrations, could be scaled to the time t as ? t(a), suggesting a diffusion-limited colloid aggregation (DLCA). The coagulation value of NaCl in a buffer at pH 7.1 was calculated to be in a range of 61.3-84.4 mM. Divalent cation Mg(2+) was far more effective in enhancing the HA coagulation, as evidenced by a lower coagulation value (between 1.0 and 1.7 mM) and a more rapid coagulation rate. Such an enhancement could be explained by the combined effects of electrostatic repulsion, complexation and bridging. The highest coagulation rate (d/dt) and coagulation value at different pHs followed the order of: acidic > neutral > alkaline, and alkaline > neutral > acidic, respectively. Such a difference was associated with the extent of hydrogen bond and electrostatic repulsion at different protonation/deprotonation states of carboxyl and phenolic -OH groups. Transmission electron microscopic imaging reveals that HA was predominantly globular aggregates with a rough periphery at pH 5.26, and was changed to smooth spherical particles at pH 10.00. These results are useful for better understanding the coagulation behaviors of HAs in both natural and engineered aqueous systems.
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In-situ utilization of generated electricity in an electrochemical membrane bioreactor to mitigate membrane fouling.
Water Res.
PUBLISHED: 04-22-2013
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How to mitigate membrane fouling remains a critical challenge for widespread application of membrane bioreactors. Herein, an antifouling electrochemical membrane bioreactor (EMBR) was developed based on in-situ utilization of the generated electricity for fouling control. In this system, a maximum power density of 1.43 W/m(3) and a current density of 18.49 A/m(3) were obtained. The results demonstrate that the formed electric field reduced the deposition of sludge on membrane surface by enhancing the electrostatic repulsive force between them. The produced H2O2 at the cathode also contributed to the fouling mitigation by in-situ removing the membrane foulants. In addition, 93.7% chemical oxygen demand (COD) removal and 96.5% NH4(+)-N removal in average as well as a low effluent turbidity of below 2 NTU were achieved, indicating a good wastewater treatment performance of the EMBR. This work provides a proof-of-concept study of an antifouling MBR with high wastewater treatment efficiency and electricity recovery, and implies that electrochemical control might provide another promising avenue to in-situ suppress the membrane fouling in MBRs.
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Facile synthesis of highly efficient and recyclable magnetic solid acid from biomass waste.
Sci Rep
PUBLISHED: 04-18-2013
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In this work, sawdust, a biomass waste, is converted into a magnetic porous carbonaceous (MPC) solid acid catalyst by an integrated fast pyrolysis-sulfonation process. The resultant magnetic solid acid has a porous structure with high surface area of 296.4 m(2) g(-1), which can be attributed to the catalytic effect of Fe. The catalytic activity and recyclability of the solid acid catalyst are evaluated during three typical acid-catalyzed reactions: esterification, dehydration, and hydrolysis. The favorable catalytic performance in all three reactions is attributed to the acids high strength with 2.57 mmol g(-1) of total acid sites. Moreover, the solid acid can be reused five times without a noticeable decrease in catalytic activity, indicating the stability of the porous carbon (PC)-sulfonic acid group structure. The findings in the present work offer effective alternatives for environmentally friendly utilization of abundant biomass waste.
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Species of phosphorus in the extracellular polymeric substances of EBPR sludge.
Bioresour. Technol.
PUBLISHED: 04-14-2013
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In this study, the species of extracellular phosphorus and their transformation during extracellular polymeric substances (EPS) extraction were explored by using (31)P nuclear magnetic resonance spectroscopy. Results show that the extraction methods had a substantial influence on the phosphorus species in the extracted EPS. Cation exchange resin method was more appropriate for extracting EPS from the enhanced biological phosphorus removal (EBPR) sludge. Orthophosphate, pyrophosphate and polyphosphate were the main species of phosphorus found to be present in the EPS, which together accounted for about 6.6-10.5% of the total phosphorus in the EBPR sludge. The high percentage of extracellular phosphorus and their diverse species might reveal a new insight into the characteristics of the phosphorus in EPS in EBPR system.
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Hydration interactions and stability of soluble microbial products in aqueous solutions.
Water Res.
PUBLISHED: 04-13-2013
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Soluble microbial products (SMP) are organic compounds excreted by microorganisms in their metabolism and decay and the main constituents in effluent from biological wastewater treatment systems. They also have an important contribution to the dissolved organic matters in natural aqueous systems. So far the interactions between SMP colloids have not been well explored. In this work, the interactions between SMP colloids in water and salt solutions were studied by using a combination of static and dynamic light scattering, Fourier transform infrared spectra, Zeta potential and acid-base titration techniques. The second osmotic virial coefficient had a larger value in a 750-mM salt solution than that in a 50-mM solution, indicating that repulsion between SMP colloids increased with an increase in salt concentration, which is contrary with the classic Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory. Such a repulsion was attributed to water structuring and enhanced by the accumulation of hydrophilic counter ions around SMP colloids and the formed hydration force. The repulsion and hydration effect led to the dispersing and deeper draining structure, accompanied by a decreased hydrodynamic radius and increased diffusion coefficient. This hydration force was related to so-called ion specific effect, and electrolyte sodium chloride had a more substantial effect on hydration force than KCl, CsCl, NaBr and NaI. Our results provide an experimental approach to explore the SMP structures, inter-colloid interactions and confirm the non-DLVO forces.
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A modeling approach to describe ZVI-based anaerobic system.
Water Res.
PUBLISHED: 04-06-2013
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Zero-valent iron (ZVI) is increasingly being added into anaerobic reactors to enhance the biological conversion of various less biodegradable pollutants (LBPs). Our study aimed to establish a new structure model based on the Anaerobic Digestion Model No. 1 (ADM1) to simulate such a ZVI-based anaerobic reactor. Three new processes, i.e., electron release from ZVI corrosion, H2 formation from ZVI corrosion, and transformation of LBPs, were integrated into ADM1. The established model was calibrated and tested using the experimental data from one published study, and validated using the data from another work. A good relationship between the predicted and measured results indicates that the proposed model was appropriate to describe the performance of the ZVI-based anaerobic system. Our model could provide more precise strategies for the design, development, and application of anaerobic systems especially for treating various LBPs-containing wastewaters.
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Phenothiazine derivative-accelerated microbial extracellular electron transfer in bioelectrochemical system.
Sci Rep
PUBLISHED: 03-21-2013
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In bioelectrochemical system (BES) the extracellular electron transfer (EET) from bacteria to anode electrode is recognized as a crucial step that governs the anodic reaction efficiency. Here, we report a novel approach to substantially enhance the microbial EET by immobilization of a small active phenothiazine derivative, methylene blue, on electrode surface. A comparison of the currents generated by Shewanella oneidensis MR-1 and its mutants as well as the electrochemical analytical results reveal that the accelerated EET was attributed to enhanced interactions between the bacterial outer-membrane cytochromes and the immobilized methylene blue. A further investigation into the process using in situ Raman spectro-electrochemical method coupled with density functional theory calculations demonstrates that the electron shuttling was achieved through the change of the molecule conformation of phenothiazine in the redox process. These results offer useful information for engineering BES.
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Toxic effects of imidazolium-based ionic liquids on Caenorhabditis elegans: the role of reactive oxygen species.
Chemosphere
PUBLISHED: 03-17-2013
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By using Caenorhabditis elegans (C. elegans) as a model animal, the present work is aimed to evaluate the acute toxicity of imidazolium-based bromide Ionic Liquids (ILs), and to elucidate the underlying mechanisms involved. Firstly, 24-h median lethal concentration (LC50) for eight ILs with different alkyl chain lengths and one or two methyl groups in the imidazolium ring were determined to be in a range of 0.09-6.64 mg mL(-1). Four ILs were selected to investigate the toxic mechanisms. Mortality, levels of reactive oxygen species (ROS), lipofuscin accumulation and expression of superoxide dismutase 3 in C. elegans were determined after exposed to ILs at sub-lethal concentrations for 12h. A significant increase in the levels of these biomarkers was observed in accordance with the results of 12-h lethality assay. The addition of 0.5% dimethyl sulfoxide, which acts as a radical scavenger, remarkably rescued the lethality of C. elegans and significantly decreased the ROS level in C. elegans. Our results suggest that ROS play an important role in IL-induced toxicity in C. elegans.
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Evaluation of three ornamental plants for phytoremediation of Pb-contamined soil.
Int J Phytoremediation
PUBLISHED: 03-16-2013
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Characteristics of accumulation and tolerance of lead (Pb) in Quamolit pennata, Antirrhinum majus L. and Celosia cristata pyramidalis were investigated to identify Pb-accumulating plants. In this study, pot culture experiment was conducted to assess whether these plants are Pb-hyperaccumulators or accumulators. The results indicated that the Pb enrichment factor (concentration in plant/soil) and Pb translocation factor (concentration in shoot/root) of these plants were principally <1 in pot culture and concentration gradient experiments. However, the Pb concentration in Celosia cristata pyramidalis shoots was higher than 1000 mg kg(-1), the threshold concentration for a Pb-hyperaccumulator. Shoot biomass of Celosia cristata pyramidalis had no significantly (p < 0.05) variation compared to the control. Based on these results, only Celosia cristata pyramidalis could be identified as a Pb-accumulator.
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Amperometric detection of dopamine in human serumby electrochemical sensor based on gold nanoparticles doped molecularly imprinted polymers.
Biosens Bioelectron
PUBLISHED: 02-23-2013
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In this work, a highly sensitive and selective biomimetic electrochemical sensor for the amperometric detection of trace dopamine (DA) in human serums was achieved by gold nanoparticles (AuNPs) doped molecularly imprinted polymers (MIPs). Functionalized AuNPs (F-AuNPs), a novel functional monomer bearing aniline moieties on the surface of the AuNPs, were prepared via a direct synthesis method and then used to fabricate the conductive MIPs film on the modified electrode by electropolymerization method in the presence of DA and p-aminobenzenethiol (p-ATP). The obtained electrochemical sensor based on the conductive film of AuNPs doped MIPs (AuNPs@MIPs) could effectively minimize the interferences caused by ascorbic acid (AA) and uric acid (UA). The linear range for amperometric detection of DA was from 0.02 ?mol L(-1) to 0.54 ?mol L(-1) with the detection limit of 7.8 nmol L(-1) (S/N=3). Furthermore, the AuNPs@MIPs modified electrode (AuNPs@MIES) was successfully employed to detect trace DA in different human serums.
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Nitrate formation from atmospheric nitrogen and oxygen photocatalysed by nano-sized titanium dioxide.
Nat Commun
PUBLISHED: 02-22-2013
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The concentration of nitrate in aquatic systems is rising with the development of modern industry and agriculture, causing a cascade of environmental problems. Here we describe a previously unreported nitrate formation process. Both indoor and outdoor experiments are conducted to demonstrate that nitrate may be formed from abundant atmospheric nitrogen and oxygen on nano-sized titanium dioxide surfaces under UV or sunlight irradiation. We suggest that nitric oxide is an intermediate product in this process, and elucidate its formation mechanisms using first-principles density functional theory calculations. Given the expanding use of titanium dioxide worldwide, such a titanium dioxide-mediated photocatalysis process may reveal a potentially underestimated source of nitrate in the environment, which on one hand may lead to an increasing environmental pollution concern, and on the other hand may provide an alternative, gentle and cost-effective method for nitrate production.
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Electron acceptor dependence of electron shuttle secretion and extracellular electron transfer by Shewanella oneidensis MR-1.
Bioresour. Technol.
PUBLISHED: 02-19-2013
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Shewanella oneidensis MR-1 is an extensively studied dissimilatory metal-reducing bacterium with a great potential for bioremediation and electricity generation. It secretes flavins as electron shuttles which play an important role in extracellular electron transfer. However, the influence of various environmental factors on the secretion of flavins is largely unknown. Here, the effects of electron acceptors, including fumarate, ferrihydrite, Fe(III)-nitrilotriacetic acid (NTA), nitrate and trimethylamine oxide (TMAO), on the secretion of flavins were investigated. The level of riboflavin and riboflavin-5-phosphate (FMN) secreted by S. oneidensis MR-1 varied considerably with different electron acceptors. While nitrate and ferrihydrite suppressed the secretion of flavins in relative to fumarate, Fe(III)-NTA and TMAO promoted such a secretion and greatly enhanced ferrihydrite reduction and electricity generation. This work clearly demonstrates that electron acceptors could considerably affect the secretion of flavins and consequent microbial EET. Such impacts of electron acceptors in the environment deserve more attention.
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miR-335 represents an invasion suppressor gene in ovarian cancer by targeting Bcl-w.
Oncol. Rep.
PUBLISHED: 02-18-2013
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microRNAs (miRNAs) are a class of non-coding small RNAs that bind to target mRNAs, usually resulting in post-transcriptional repression by translational inhibition or target degradation. mRNAs can function as tumor suppressors or oncogenes (also referred to as oncomirs) in human tumors. Although aberrant expression of miR-335 has been reported in ovarian cancer, whether it is an active participant or a mere bystander remains unknown. To clarify its role in ovarian carcinogenesis, we first examined the relative expression of miR-335 in 17 normal ovarian tissues and 4 ovarian cancer cell lines using qPCR. We found that miR-335 was downregulated in the ovarian cancer cell lines relative to normal ovarian epithelium tissues. In vitro, overexpression of miR-335 suppressed cell migration and invasion and resulted in depolymerization of F-actin in ovarian cancer cell lines, but exhibited a negligible effect on cell proliferation. B-cell CLL/lymphoma 2 like 2 (Bcl-w or BCL2L2), a pro-survival member of the Bcl-2 protein family, was identified as a potential target of miR-335 according to the results of bioinformatic analysis, and the expression of Bcl-w and its effector matrix metalloproteinase-2 (MMP?2) was downregulated after transfection with miR-335 mimics. In addition, ectopic Bcl-w could almost fully nullify the effect of miR-335 overexpression on ovarian cancer cell migration and invasion. These findings indicate that the tiny genome product, miR-335, whose lack of expression brings about the abnormal accumulation of Bcl-w and subsequent unchecked cell invasion in ovarian cancer, may help us to understand one of the many steps ovarian cells take on their way toward the acquisition of malignant phenotypes and miR-335 may be a promising predictor of survival.
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Linear measurements of healthy adults coronal section of hippocampus on brain magnetic resonance imaging.
J Craniofac Surg
PUBLISHED: 01-26-2013
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To figure out hippocampal anatomy features, which can be used as reference in determination of hippocampus-related disease, we rebuilt 3-dimensional brain models with magnetic resonance imaging; then, we chose 1 coronal section of the hippocampus and took 22 linear measurements of each section in 74 healthy adults. In each section, we took paired sample T test for the left and right measurements comparison, independent sample T test for sex difference comparison, and correlation analysis for relationships between age and other measurements. For the left and right comparison, 9 measurements have no significant difference (P > 0.05). For sex difference, 8 measurements have significant differences (P < 0.05). In age linear regression analysis, 5 measurements have significance in statistical analysis. All results above demonstrate that measurements of this section have little significance in L/R difference, but for different sexes, these measurements show significant results, which means male and female were different. As for age linear regression analysis, brain shape and distances were age related. This study provides reference for diagnosis of hippocampal atrophy, and it is an easy approach instead of areal and volumetric measurements in clinical practice.
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Synthesis, characterization and application of a novel starch-based flocculant with high flocculation and dewatering properties.
Water Res.
PUBLISHED: 01-25-2013
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Flocculation process is one of the most widely used techniques for water and wastewater treatment, and also for sludge dewatering. Synthesis of natural biopolymers or modification of natural biopolymers as environmentally friendly flocculants is highly desired in the field of environmental protection. In this work, a water soluble copolymer flocculant, STC-g-PDMC (starch-graft-poly (2-methacryloyloxyethyl) trimethyl ammonium chloride) was synthesized through grafting a monomer, (2-methacryloyloxyethyl) trimethyl ammonium chloride (DMC), onto starch initiated by potassium persulphate. Acetone and ethanol were used for copolymer precipitation and purification in the synthesis, which diminished the toxicity during the synthesis process. The graft copolymer was characterized using Fourier-transform infrared spectroscopy, (1)H nuclear magnetic resonance, X-ray powder diffraction, thermogravimetric analysis and elemental analysis. The prepared STC-g-PDMC exhibited a highly effective flocculation capability for kaolin suspensions compared with starch and polyacrylamide as control. The charge neutralization effect played an important role in the flocculation process at low flocculant dosages. When it was used as dewatering agent for anaerobic sludge, the conditioned sludge could be easily filtered after the dosage reached 0.696% of the dry weight of sludge. Such a graft copolymer is a promising green agent for wastewater treatment and sludge dewatering applications.
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A novel electrochemical membrane bioreactor as a potential net energy producer for sustainable wastewater treatment.
Sci Rep
PUBLISHED: 01-23-2013
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One possible way to address both water and energy shortage issues, the two of major global challenges, is to recover energy and water resource from wastewater. Herein, a novel electrochemical membrane bioreactor (EMBR) was developed to recover energy from wastewater and meantime harvest clean water for reuse. With the help of the microorganisms in the biocatalysis and biodegradation process, net electricity could be recovered from a low-strength synthetic wastewater after estimating total energy consumption of this system. In addition, high-quality clean water was obtained for reuse. The results clearly demonstrate that, under the optimized operating conditions, it is possible to recover net energy from wastewater, while at the same time to harvest high-quality effluent for reuse with this novel wastewater treatment system.
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A photometric high-throughput method for identification of electrochemically active bacteria using a WO3 nanocluster probe.
Sci Rep
PUBLISHED: 01-18-2013
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Electrochemically active bacteria (EAB) are ubiquitous in environment and have important application in the fields of biogeochemistry, environment, microbiology and bioenergy. However, rapid and sensitive methods for EAB identification and evaluation of their extracellular electron transfer ability are still lacking. Herein we report a novel photometric method for visual detection of EAB by using an electrochromic material, WO(3) nanoclusters, as the probe. This method allowed a rapid identification of EAB within 5?min and a quantitative evaluation of their extracellular electron transfer abilities. In addition, it was also successfully applied for isolation of EAB from environmental samples. Attributed to its rapidness, high reliability, easy operation and low cost, this method has high potential for practical implementation of EAB detection and investigations.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.