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1.
Water Res ; 173: 115536, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-32032886

RESUMO

Taking advantage of the high mass transfer in the bulk solution of fluidized-bed reactor (FBR), and the benefits of simultaneous particle separation and ozone catalysis on ceramic membranes, we proposed a hybrid fluidized-bed reactor (HFBR) based on arrayed ceramic membranes (ACMs) coupled with powdered activated carbon (PAC) for efficient catalytic ozonation. The optimum HFBR performance on a pilot scale was found at PAC addition of 3 g/L, ozone dosage of 25 mg/L, hydraulic retention time of 60 min and auxiliary aeration strength of 5 m3/h. During the 30-day treatment of coal-gasification secondary effluent (200 L/h), the HFBR system revealed not only a 117% increase in ozone utilization efficiency (ΔCOD/ΔO3) upon pure ozonation but also a highly purified effluent with better sterilization and low residual bromate (∼11 µg/L). Low-molecular-weight organic fragments and acids, as well as phthalate esters were identified as the main products in this process. By density functional theory (DFT) calculations, it was found the main functional groups (carbonyls, -C=O) on the PAC could be protected from direct ozonation in the presence of ozone-degradable organics (e.g. phenolic and aliphatic compounds) in the wastewater through an ozone-competing reaction, which prevented the rapid inactivation of the PAC in catalytic ozonation. A longer service life and cheaper materials for ceramic membranes would benefit low operation costs for the HFBR. Moreover, the addition of PAC could greatly reduce ozone demand by ∼60% in the HFBR, and therefore decrease energy consumption by ∼30%. Hence, the HFBR was proved to be a highly competitive technology for wide application in the near future.

2.
Water Res ; 172: 115493, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31978838

RESUMO

Bioelectrochemical system (BES) is promising technology to simultaneously treat wastewater and recover energy, and electrode material is important for the system performance. Microbial fuel cell (MFC) is one of typical BES to be applied in wastewater treatment. How to improve the electrode material is significant to improve wastewater treatment, energy recovery and cost effectiveness. In this study, 3D-weaved carbon electrode entity, assembled by multiple pieces of carbon mesh (CM), was proposed to combine all electrode components as entity to facilitate electron conduction and ionic migration, compared with carbon brush (CB) and granular activated carbon (GAC). The result showed that current density and internal resistance of MFC using 3D-weaved CM as horizontally extended inside anode (CM(T)) were 30.9 A m-3 and 4.5 Ω, respectively, with higher output than traditional GAC (22.6 A m-3 and 6.2 Ω). Though GAC had greater electrode filling and surface area for biomass growth, the electron transfer efficiency per unit electrode biomass was only at 0.0019 ± 0.0002 mol g-1 d-1, much lower than CM(T) at 0.0077 ± 0.0009 mol g-1 day-1. Higher ionic migration rate of CM(T) suggested the assisting effect of composite electrode to enhance ionic transportation towards the cathode. Microbial analysis further indicated that 3D-CM electrode network could simultaneously enhance Geobacter abundance and methanogen activity, suggesting the importance of electrode network on electricigens. Furthermore, CM(T) could obtain 10 times higher energy output efficiency than traditional GAC when applied inside anode chamber. This study proved that network construction of anode electrode could promote the electrode performance and cost effectiveness, suggesting the future development of reactor design of bioelectrochemical system.

3.
Food Chem ; 310: 125868, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31767484

RESUMO

The aim of this research was to investigate the effect of herring roe phospholipids (PLs) on the oxidative stability of cod liver oil during storage. The effect of PLs on the oxidative stability of cod liver oil was assessed in terms of peroxide value, free fatty acids, secondary oxidation products and pyrrolisation. The results show that the PV was lower in cod liver oil containing PLs (P < 0.05) than in the control without PLs. Benzaldehyde, 2,5-dimethylpyrazine, 2-methyl-2-pentenal, 1-penten-3-ol and 3-methylbutanal were the main volatiles. In addition, significant pyrrolisation was observed after 28 days when PLs were added to cod liver oil. The results suggested that cod liver oil with dispersed PLs was oxidized during storage followed by non-enzymatic browning reactions. The findings indicated that the ratio between pyrroles formed and α-tocopherol may influence the formation of new peroxides and secondary oxidation products.

4.
Environ Sci Technol ; 54(2): 1177-1185, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31829572

RESUMO

Flow-electrode electrochemical desalination (FEED) processes (e.g., flow-electrode capacitive deionization), which use flowable carbon particles as the electrodes, have attracted increasing attention, holding the promise for continuous desalination and high desalting efficiency. While it is generally believed that carbon particles with abundant microporous and large specific capacitances (e.g., activated carbon, AC) should be ideal candidates for FEED electrodes, we provide evidence to the contrary, showing that highly conductive electrodes with low specific surface area can outperform microporous AC-based electrodes. This study revealed that FEED using solely high surface area AC particles (∼2000 m2 g-1, specific capacitance of ∼44 F g-1, average salt adsorption rate of ∼0.15 µmol cm-2 min-1) was vastly outperformed by electrodes based solely on low-surface area carbon black (CB, ∼70 m2 g-1, ∼0.5 F g-1, ∼0.75 µmol cm-2 min-1). Electrochemical impedance spectroscopy results suggest that the electrode formed by CB particles led to more effective electronic charge percolation, likely contributing to the improved desalination performance. In addition, we propose and demonstrate a novel operation mode, termed single cycle (SC), which greatly simplified the FEED cell configuration and enabled simultaneous charging and discharging. Using SC mode with CB flow electrodes delivered an increased average salt removal rate relative to the more traditional short-circuited closed cycle (SCC) mode, achieving up to 1.13 µmol cm-2 min-1. Further investigations demonstrate that up to 50% of energy input would be avoided when using CB flow electrodes operated under SC mode as compared to that of AC flow electrodes operated under SCC mode. In summary, the FEED process presented in this study provided an innovative and promising approach toward high-efficient and low-cost brackish water desalination.

5.
Sci Total Environ ; 705: 135921, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31818602

RESUMO

Changes in the biogeochemical cycling of mercury (Hg) and Hg species were investigated in a typical marine aquaculture area located at Zhoushan island, Zhejiang province, east China. Mercury species were analyzed in different environmental samples collected during a field survey and a simulation batch experiment. The field work comprised both summer and winter collection of water and sediment samples from marine aquaculture sites (MAS) in a field survey and from corresponding reference sites (CRS) located 2500 m from the MAS. THg concentrations in water were 91.3 ± 70.3 and 115 ± 22.6 pmol L-1 in summer and winter, respectively. Particulate Hg accounting for ˃60% of THg and positively correlated with total suspended solid content in water. Dissolved organic carbon in water was positively correlated with dissolved Hg. Significantly higher (p < 0.001, F = 102) total methylmercury (TMeHg) contents were observed in MAS (0.31 ± 0.26 ng g-1) than in CRS (0.06 ± 0.03 ng g-1) in the sediment solid phase. Moreover, MeHg formation rate in MAS was clearly higher than in CRS in the simulation experiment. Both the field survey and the simulation experiment highlighted the readier formation of MeHg in MAS than in CRS. TMeHg levels in blackhead seabream (Acanthopagrus schlegelii), red snapper (Lutjanus campechanus) and perch (Perca fluviatilis) were only 52.7 ± 5.74, 23.7 ± 2.51 and 24.3 ± 3.86 ng g-1, values significantly lower than the safety guideline (1000 ng g-1) established by the World Health Organization.

6.
Water Res ; 171: 115390, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31865129

RESUMO

The knowledge about membrane biofouling evolution in full-scale membrane bioreactor (MBR) applications is quite lacking, notwithstanding a few lab-scale investigations. For the first time, this study elaborated the effect of online NaOCl cleaning on the dynamic development of membrane biofilm microbiota during long-term operation of a large-scale MBR for municipal wastewater treatment (40,000 m3/d). Four times of membrane autopsies were conducted during 160 days operation to scrutinize the microbial community and concomitant organic foulants. The transmembrane pressure difference (TMP) development revealed limited effect of 30 min online NaOCl cleaning on long-term biofouling removal. NaOCl not only altered the structure of biofilm communities but also increased the richness and evenness on early fouling stages. Meanwhile, network analysis revealed the keystone taxa f_Comamonadaceae that played key roles in stabilizing community structure and developing anti-cleaning and irreversible fouling propensity of the biofilm. NaOCl cleaning also impacted the evolving of keystone taxa by intensifying the competition between the dominated taxa f_Moraxellaceae and other species during early fouling stages. Furthermore, the succession of the biofilm microbiota synchronously accelerated the TMP increase and the accumulation of organic foulants including polysaccharides, aromatic proteins and soluble microbial products during biofilm maturation. These identified key stubborn foulants shed light on limitations of current online NaOCl cleaning and provide guidance to optimize the efficiency of online chemical cleaning protocols in full-scale MBR operations.


Assuntos
Incrustação Biológica , Membranas Artificiais , Autopsia , Reatores Biológicos , Águas Residuárias
7.
J Environ Manage ; 253: 109691, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31630062

RESUMO

To investigate the effect of the organic loading rate (OLR) on anaerobic treatment of monosodium glutamate (MSG) wastewater, a lab-scale up-flow anaerobic blanket (UASB) reactor was continuously operated over a 222-day period. The overall performances of COD removal and methane recovery initially exhibited an increase and subsequently decreased when the OLR was increased from 1 g-COD/L/d to 24 g-COD/L/d. At the optimal OLR of 8 g-COD/L/d, superior performance was obtained with a maximum COD removal efficiency of 97%, a methane production rate of 2.3 L/L/d, and specific methanogenic activity of 86 mg-CH4/g-VSS/d (feeding on glutamate), with superior characteristics of sludge in VSS concentration, average diameter of granules, and settling velocity. According to the results of the specific methanogenic activity, the methanogenic pathway was more inclined to pass through acetate than through hydrogen. Methanosarcina instead of Methanosaeta, with Methanobacterium and greatly increased Firmicutes, dominated in the UASB reactor after long term operation. These results support that the OLR had a substantial effect on both the treatment and energy recovery efficiency of MSG wastewater as well as on microbial community variations in the UASB reactor.


Assuntos
Microbiota , Esgotos , Anaerobiose , Reatores Biológicos , Metano , Glutamato de Sódio , Eliminação de Resíduos Líquidos , Águas Residuárias
8.
Bioelectrochemistry ; 131: 107395, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31704456

RESUMO

To understand electron transport in electrochemically active biofilms, it is necessary to elucidate the heterogeneous electron transport across the biofilm/electrode interface and in the interior of G. sulfurreducens biofilms bridging gaps of varying widths. The conductivity of Geobacter sulfurreducens biofilm bridging nonconductive gaps with widths of 5µm, 10µm, 20µm and 50µm is investigated. Results of electrochemical gating measurement show that biofilm conductivity peaks at the potential of -0.35V vs. Ag/AgCl. The biofilm conductivity increases with gap width (10.4±0.2µScm-1 in 5µm gap, 13.3±0.2µScm-1 in 10µm gap, 16.7±1.4µScm-1 in 20µm gap and 41.8±2.02µScm-1 in 50µm gap). These results revealed that electron transfer in G. sulfurreducens biofilm is a redox-driven. In addition, higher biofilm conductivities and lower charge transfer resistances are observed in all gaps under a turnover condition than in those under a non-turnover condition. Our results offer insights into the spatial heterogeneity of biofilm structure and extracellular electron transfer in electrochemically active biofilms.


Assuntos
Biofilmes , Condutividade Elétrica , Eletrodos , Geobacter/metabolismo , Transporte de Elétrons
9.
J Sci Food Agric ; 100(1): 315-324, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31525262

RESUMO

BACKGROUND: In order to utilize tilapia skin gelatin hydrolysate protein, which is normally discarded as industrial waste in the process of fish manufacture, we study the in vivo and in vitro angiotensin-I-converting enzyme (ACE) inhibitory activity of the peptide Leu-Ser-Gly-Tyr-Gly-Pro (LSGYGP). The aim was to provide a pharmacological basis of the development of minimal side effects of ACE inhibitors by comparative analysis with captopril in molecular docking. RESULTS: This peptide from protein-rich wastes showed excellent ACE inhibitory activity (IC50  = 2.577 µmol L-1 ) and exhibited a mixed noncompetitive inhibitory pattern with Lineweaver-Burk plots. Furthermore, LSGYGP and captopril groups both showed significant decreases in blood pressure after 6 h and maintained good digestive stability over 4 h. Molecular bond interactions differentiate competitive captopril upon hydrogen bond interactions and Zn(II) interaction. The C-terminal Pro generates three interactions (hydrogen bonds, hydrophilic interactions and Van der Waals interactions) in the peptide and effectively interacts with the S1 and S2 pockets of ACE. CONCLUSION: LSGYGP, with an IC50 value of 2.577 µmol L-1 , has an antihypertensive effect in spontaneously hypertensive rats. Through comparison with captopril, this study revealed that LSGYGP may be a potential food-derived ACE inhibitory peptide and could act as a functional food ingredient to prevent hypertension. © 2019 Society of Chemical Industry.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Anti-Hipertensivos/química , Captopril/química , Hipertensão/tratamento farmacológico , Peptídeos/química , Sequência de Aminoácidos , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/metabolismo , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Captopril/administração & dosagem , Ciclídeos , Digestão , Proteínas de Peixes/química , Trato Gastrointestinal/metabolismo , Humanos , Ligações de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Cinética , Masculino , Simulação de Acoplamento Molecular , Peptídeos/metabolismo , Peptídeos/farmacologia , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Hidrolisados de Proteína/química , Hidrolisados de Proteína/metabolismo , Ratos , Ratos Endogâmicos SHR
10.
Small ; : e1905240, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31755227

RESUMO

Microbial fuel cells (MFCs) can convert organics in wastewater directly to electricity, and improving oxygen reduction reaction (ORR) performance is critical to their development and future applications. Electrocatalytic ORR performance is determined by the intrinsic activity and accessible amounts of active sites. A surface nitrogen-enriched carbon coaxial nanocable (NCCN) is applied as an ORR electrocatalyst and combined with activated carbon (AC) with 80 wt% addition as a carbon-carbon composite air cathode in MFCs. The fully exposed nitrogen active sites of NCCN contribute to the enhanced ORR activity, while the graphitized core affords a rapid pathway for electron transportation. AC serves as a spacer to construct a porous framework with interconnected ion diffusion channels. This cathode thus exhibits a maximum power density of 2090 mW m-2 , 120% higher than commercial Pt/C electrocatalysts, and also 6% higher than the pure NCCN, indicating a synergistic effect between NCCN and AC. A high-performance NCCN-AC air cathode with a great promise for future MFC applications is reported and an effective strategy to bridge the electrocatalytic performance from nanomaterials to practical devices is presented.

11.
Sci Total Environ ; 695: 133876, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31756846

RESUMO

Anaerobic digestion is an effective biological treatment process that produces methane by degrading organic compounds in waste/wastewater. It is a complicated microbial process by metabolic interactions among different types of microorganisms. In this process, efficient interspecies electron transfer between secondary fermenting bacteria and methanogens is the critical process for fast and effective methanogenesis. In syntrophic metabolism, hydrogen or formate has been considered as the conventional electron carrier transferring electrons from secondary fermenting bacteria to hydrogenotrophic methanogens. Recently, direct interspecies electron transfer (DIET) without the involvement of dissolved redox mediators is arousing great concerns and has been regarded as a more efficient and thermodynamically favorable interspecies electron transfer pathway for methanogenesis. Interspecies electron exchange through DIET is accomplished via the membrane-bound cytochromes or conductive pili. Several kinds of exogenously-added conductive or semiconductive iron oxides have been discovered to greatly enhance anaerobic methanogenesis through promoting DIET. Different (semi)conductive iron oxides give a boost to DIET through different mechanisms based on the physicochemical properties of the iron oxides and the reciprocal interactions between iron oxides and functional microorganisms. In this review, the current understanding of interspecies electron transfer in syntrophic-methanogenic consortions is summarized, the effects and deep-rooted mechanisms of (semi)conductive iron oxides on methanogenesis and DIET are discussed, and possible future perspectives and development directions are suggested for DIET via (semi)conductive iron oxides in anaerobic digestion.


Assuntos
Biodegradação Ambiental , Anaerobiose , Bactérias/metabolismo , Reatores Biológicos , Transporte de Elétrons , Elétrons , Fermentação , Compostos Férricos , Metano/metabolismo , Semicondutores
12.
Food Nutr Res ; 632019.
Artigo em Inglês | MEDLINE | ID: mdl-31762729

RESUMO

Introduction: A previous study has shown that Ala-Thr-Pro-Gly-Asp-Glu-Gly (ATPGDEG) peptide identified from boiled abalone by-products has high antioxidant activities and antihypertensive effect. Objective: In this study, we further investigated its antiphotoaging activities by ultraviolet B (UVB)-induced HaCaT cells. Result: UVB irradiation significantly increased the content of intercellular reactive oxygen species (ROS) and the production of matrix metalloproteinases (MMPs) in HaCaT cells and decreased its content of collagen. First, the generation of intercellular ROS was reduced by abalone peptide in UVB-induced HaCaT cells. And activities of MMP-1 and MMP-9 were reduced by abalone peptide in a dose-dependent manner. Furthermore, western blot analysis demonstrated that abalone peptide downregulated the expression of p38, c-Jun N-terminal kinases, and extracellular signal-regulated kinases via mitogen-activated protein kinases (MAPKs) and NF-κB signaling to protect type I pro collagen and DNA damage. Molecular docking simulation confirms that abalone peptide inhibited activities of MMP-1 and MMP-9 by docking their active site, among them N-terminal Ala, C-terminal Gly, and Pro at the third position of N-terminal made a great contribution. Conclusion and recommendation: Abalone peptide could protect type I procollagen synthesis in UVB-irradiated HaCaT cells, and it is a potential peptide for the treatment of skin photoaging in the future.

13.
Simul Healthc ; 14(6): 372-377, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31652180

RESUMO

BACKGROUND: Previous studies demonstrated that pretraining video-assisted debriefing (VAD) with trainees' errors (TE) videotaped in a skills pretest improved skill learning of basic life support (BLS). However, conducting a pretest and preparing TE video examples is resource intensive. Exposing individual trainee's errors to peers might be a threat to learners' psychological safety. We hypothesized pretraining VAD with simulated errors (SE, performed by actors) might have the same beneficial effect on skills learning as pretraining VAD with TE, but avoid drawbacks of TE. METHODS: Three hundred twenty-two third-year medical students were randomized into 3 groups (the control [C], TE, SE). A videotaped BLS skills pretest was conducted in 3 groups. Then, group C received traditional training with concurrent feedback. Video-assisted debriefing with TE in the pretest or SE was delivered in groups TE or SE, respectively, followed by BLS training without any feedback. Basic life support skills were retested 1 week later (posttest). Students completed a survey to express their preference to TE or SE for VAD in the future. RESULTS: Higher BLS skills scores were observed in groups TE (85.7 ± 7.0) and SE (86.8 ± 7.5) in the posttest, compared with group C (68.7 ± 13.3, P < 0.001). No skills difference was observed between group TE and SE in the posttest. More trainees (65.8%) preferred SE for VAD. CONCLUSIONS: Pretraining VAD with SE had an equivalent beneficial effect as VAD with TE on BLS skills learning in medical students. More trainees preferred SE for VAD with regard to psychological safety.

14.
Cell Death Dis ; 10(10): 717, 2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31558707

RESUMO

Accumulating evidence indicates long noncoding RNAs (lncRNA) play a vital role in tumor progression. However, the role of linc00645-induced accelerated malignant behavior in glioblastoma (GBM) remains unknown. In the present study, linc00645 expression was significantly upregulated in GBM tissues and cell lines. High level of linc00645 was associated with poor overall survival in GBM patients. Knockdown of linc00645 suppressed the proliferation, stemness, migration, invasion, and reversed transforming growth factor (TGF)-ß-induced motility of glioma cell lines. Furthermore, linc00645 directly interacted with miR-205-3p and upregulated of miR-205-3p impeded efficiently the increase of ZEB1 induced by linc00645 overexpression. Moreover, knockdown of linc00645 significantly suppressed the progression of glioma cells in vivo. miR-205-3p was a target of linc00645 and linc00645 modulates TGF-ß-induced glioma cell migration and invasion via miR-205-3p. Taken together, our findings identified the linc00645/miR-205-3p/ZEB1 signaling axis as a key player in EMT of glioma cells triggered by TGF-ß. These data elucidated that linc00645 plays an oncogenic role in glioma and it may serve as a prognostic biomarker and a potential therapeutic target for the treatment of glioma in humans.

15.
Ecotoxicol Environ Saf ; 183: 109549, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31408818

RESUMO

Paspalum distichum L. was tested to evaluate its ability to phytoremediate mercury (Hg) contaminated soil over a 60-d period by analysis of the total Hg concentrations in roots and leaves. Hg concentration in Hg-contamination soil decreased by 70.0 µg g-1 after 60 day of grass cultivation and Hg was readily taken up by the roots (4.51 ±â€¯1.90 µg g-1) rather than the leaves (0.35 ±â€¯0.02 µg g-1). In addition, a comparative proteomic study was performed to unravel the protein expression involved in the Hg stress response in P. distichum L. A total of 49 proteins were classified as differentially proteins in the roots by the 'top three' proteomic analysis, of which 32 were up-regulated and 17 down-regulated in response to Hg stress. These changed proteins were classified by gene ontology analysis into five complex molecular functions involving photosynthesis and energy metabolism (31%), oxidative stress (14%), protein folding (16%), sulfur compound metabolism (10%), metal binding, and ion transport (29%). Moreover, the protein expression patterns were consistent with the metabolism pathway results. Overall, the results contribute to our understanding of the molecular mechanisms of the Hg response in P. distichum and we propose a theoretical basis for the phytoremediation of Hg-contaminated soils.


Assuntos
Mercúrio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Paspalum/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Regulação para Baixo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mercúrio/metabolismo , Estresse Oxidativo/genética , Paspalum/genética , Paspalum/metabolismo , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Proteômica , Poluentes do Solo/metabolismo , Regulação para Cima
16.
Sci Rep ; 9(1): 12162, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434924

RESUMO

Multi-structured Ag/MnO2-cordierite molded catalysts were prepared by hydrothermal method and applied to the catalytic oxidation of VOCs. Catalytic activities of Ag/MnO2-cordierite were evaluated by 1000 ppm of toluene, ethyl acetate and chlorobenzene degradation respectively at the air atmosphere, and their physicochemical properties were characterized through multiple techniques containing XRD, SEM, TEM, H2-TPR and XPS. It is found that nanorod Ag/MnO2-cordierite molded catalyst showed prominent catalytic activity for VOCs decomposition and the T90 for toluene, ethyl acetate and chlorobenzene are 275 °C, 217 °C and 385 °C respectively under the space velocity of 10,000 h-1. High valence manganese oxide, more active lattice oxygen proportion and superior low-temperature reducibility were the great contributors to the high activity of the catalyst with nanorod morphology. Studies of space velocity and catalytic stability over nanorod Ag/MnO2-cordierite molded catalyst have confirmed the good catalytic performance, excellent mechanical strength and satisfied anti-toxicity to Cl at higher space velocity, which indicates that this molded catalyst have promise for industrial application.

17.
Sci Total Environ ; 695: 133823, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31421333

RESUMO

Sulfur autotrophic denitrification has been proved feasible for nitrate removal from aquatic environments and it utilizes elemental sulfur as the electron donor. A maximum denitrification rate of 194.57 mg N/L·d was achieved with biogenic sulfur as electron donor in a mixed culture collected from sulfur packed bed reactors; this rate was considerably higher than that delivered by α-S8 or µ-S in the same mixed culture. The elemental sulfur was also tested in the pure culture of Thiobacillus denitrificans, while a lower denitrification rate was noted than in the mixed culture, bio-S (4.86 mg N/L·d) again outperformed other two elemental sulfur's. X-ray absorption near edge structure spectra were collected to examine possible metabolic intermediates during the sulfur autotrophic denitrification process. The analysis revealed the existence of two major intermediates: DL-cysteine and L-cystine. They were found to not only provide electrons but also play a critical role in promoting the elemental sulfur-mediated sulfur autotrophic denitrification process. In general, we investigated the formation and enhancement effects of sulfur intermediates in the sulfur autotrophic denitrification process.


Assuntos
Biodegradação Ambiental , Desnitrificação/fisiologia , Nitrogênio/metabolismo , Processos Autotróficos , Cisteína , Cistina , Enxofre/metabolismo , Thiobacillus/metabolismo
18.
Mar Drugs ; 17(9)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438457

RESUMO

The phospholipids (PLs) of large yellow croaker (Pseudosciaena crocea, P. crocea) roe contain a high level of polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), which can lower blood lipid levels. In previous research, PLs of P. crocea roe were found able to regulate the accumulation of triglycerides. However, none of these involve the function of DHA-containing phosphatidylcholine (DHA-PC), which is the main component of PLs derived from P. crocea roe. The function by which DHA-PC from P. crocea roe exerts its effects has not yet been clarified. Herein, we used purified DHA-PC and oleic acid (OA) induced HepG2 cells to establish a high-fat model, and the cell activity and intracellular lipid levels were then measured. The mRNA and protein expression of Fatty Acid Synthase (FAS), Carnitine Palmitoyl Transferase 1A (CPT1A) and Peroxisome Proliferator-Activated Receptor α (PPARα) in HepG2 cells were detected via RT-qPCR and western blot as well. It was found that DHA-PC can significantly regulate triglyceride accumulation in HepG2 cells, the effect of which was related to the activation of PPARα receptor activity, upregulation of CPT1A, and downregulation of FAS expression. These results can improve the understanding of the biofunction of hyperlipidemia mediated by DHA-PC from P. crocea roe, as well as provide a theoretical basis for the utilization of DHA-PC from P. crocea roe as a functional food additive.

19.
J Exp Clin Cancer Res ; 38(1): 380, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462285

RESUMO

BACKGROUND: Accumulating evidence demonstrates the oncogenic roles of lncRNA (long non-coding RNA) molecules in a wide variety of cancer types including glioma. Equally important, However, tumorigenic functions of lncRNA in glioma remain largely unclear. A recent study suggested lncRNA SNHG15 played a role for regulating angiogenesis in glioma but its role in the tumor microenvironment (TME) was not investigated. METHODS: First, we showed that SNHG15 was upregulated in GBM cells and associated with a poor prognosis for the patients of GBM using public databases. Next, we collected temozolomide sensitive (TMZ-S) and resistant (TMZ-R) clinical samples and demonstrated that co-culturing TMZ-R cells with HMC3 (microglial) cells promoted M2-polarization of HMC3 and the secretion of pro-GBM cytokines TGF-ß and IL-6. RESULTS: Comparative qPCR analysis of TMZ-S and TMZ-R cells showed that a significantly higher level of SNHG15, coincidental with a higher level of Sox2, ß-catenin, EGFR, and CDK6 in TMZ-R cells. Subsequently, using bioinformatics tool, a potential mechanistic route for SNHG15 to promote GBM tumorigenesis was by inhibiting tumor suppressor, miR-627-5p which leads to activation of CDK6. Gene-silencing technique was employed to demonstrate that suppression of SNHG15 indeed led to the suppression of GBM tumorigenesis, accompanied by an increase miR-627-5p and decreased its two oncogenic targets, CDK6 and SOX-2. In addition, SNHG15-silenced TMZ-R cells became significantly sensitive towards TMZ treatment and less capable of promoting M2-phenotype in the HMC3 microglial cells. We then evaluated the potential anti-GBM activity of CDK6 inhibitor, palbociclib, using TMZ-R PDX mouse models. Palbociclib treatment significantly reduced tumorigenesis in TMZ-R/HMC3 bearing mice and SNHG15 and CDK6 expression was significantly reduced while miR-627-5p level was increased. Additionally, palbociclib treatment appeared to overcome TMZ resistance as well as reduced M2 markers in HMC3 cells. CONCLUSION: Together, we provided evidence supporting the usage of CDK6 inhibitor for TMZ-resistant GBM cases. Further investigation is warranted for the consideration of clinical trials.

20.
Water Res ; 164: 114904, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31382149

RESUMO

This study employed a titanium mesh-membrane assembly (MMA) as the current collector in flow-electrode capacitive deionization (FCDI) device (designated as M-FCDI), and obtained a much reduced charge transport distance as compared to traditional FCDI with plate-shaped current collectors located far from the exchange membrane. The average salt removal rate of M-FCDI was greatly improved by 76% under 10 wt% carbon content than the control experiment with graphite plate as current collector, and the charge efficiency remained over 75% even under low carbon loading. This improvement was attributed to the reduced resistance as revealed by electrochemical impedance spectroscopy tests. Further investigation on FCDI's performance with different specifications of titanium meshes showed that the implementation of MMA could provide a larger effective electron transfer area, which would lead to better desalting performance.


Assuntos
Titânio , Purificação da Água , Eletrodos , Cloreto de Sódio , Telas Cirúrgicas
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