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2.
Artigo em Inglês | MEDLINE | ID: mdl-32454298

RESUMO

Grass carp is one of the most important freshwater aquaculture species in China. However, the mechanisms underlying the growth of muscle tissue in the fish are unclear. High-throughput RNA-Seq was used to analyze the transcriptome of grass carp muscle tissue between fast- and slow-growing fish family groups. Twenty-four individuals each from 4 fast-growing families and 4 slow-growing families were used to reduce background noise. 71 up-regulated and 35 down-regulated genes were identified in the differentially expressed genes (DEGs). GO and KEGG enrichment analyses revealed the DEGs were involved in the GH/IGF axis, calcium metabolism, protein and glycogen synthesis, oxygen transport, cytoskeletal and myofibrillar components. IGFBP1 was up-regulated in big fish while GHR2 was down-regulated. Glutamic pyruvate transaminase 2, an indicator of liver tissue damage, was down-regulated in big grass carp, which indicates that the fish was better adapted to an artificially formulated diet. GAPDH, the rate-limiting enzyme in glycolytic flux was highly expressed in fast-growing grass carp, reflecting enhanced carbohydrate metabolism. Higher expression of ALAS2 and myoglobin 1 in big grass carp, related to oxygen transport might promote aerobic exercise along with food intake and muscle growth. Genes for cytoskeletal and myofibrillar components such as tropomyosin, meromyosin, and troponin I were also up-regulated in big grass carp. These results provide valuable information about the key genes for use as biomarkers of growth in selective breeding programs for grass carp and contribute to our understanding of the molecular mechanisms and regulative pathways regulating growth in fish.

3.
Nanoscale ; 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32409798

RESUMO

The development of efficient electrocatalysts for overall water splitting is important for future renewable energy systems. Herein, macroporous CoO covered by Co/N-doped graphitic carbon nanosheet arrays (mac-CoO@Co/NGC NSAs) were constructed by engineering a mesoporous CoO nanowire (mes-CoO NWAs) core with highly conductive Co nanoparticles coated by a N-doped graphitic carbon (Co/NGC) shell. The in situ derived Co/NGC shell not only introduces electrocatalytic active sites for the hydrogen evolution reaction (HER) but also promotes the oxygen evolution reaction (OER) through the strong interaction between the CoO core and the Co/NGC shell. Moreover, the highly conductive Co/NGC shell crosslinks the isolated mesoporous CoO nanowires into a nanosheet rich in macropores, ensuring effective electron and mass transfer. Furthermore, the chemically stable N-doped graphitic carbon layer and physically stable hierarchical nanosheet arrays ensure the stability of the catalyst. Owing to the desirable interfaces and pore architecture, the as-prepared mac-CoO@Co/NGC NSAs can serve as highly effective, binder-free electrocatalysts for overall water splitting with a stable cell voltage of 1.62 V at 10 mA cm-2 for 35 h.

4.
Cell Biol Int ; 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32437058

RESUMO

The objective of this project was to find a bronchodilatory compound from herbs and clarify the mechanism. We found that the ethanol extract of Folium Sennae (EEFS) can relax airway smooth muscle (ASM). EEFS inhibited ASM contraction induced by acetylcholine in mouse tracheal rings and lung slices. High-performance liquid chromatography (HPLC) assay showed that EEFS contained emodin. Emodin had a similar reversal action. Acetylcholine-evoked contraction was also partially reduced by nifedipine (a selective inhibitor of L-type voltage-dependent Ca2+ channels, LVDCCs), YM-58483 (a selective inhibitor of store-operated Ca2+ entry, SOCE), as well as Y-27632 (an inhibitor of Rho-associated protein kinase, ROCK). In addition, LVDCC- and SOCE-mediated currents and cytosolic Ca2+ elevations were inhibited by emodin. Emodin reversed acetylcholine-caused increases of phosphorylation of myosin phosphatase target subunit 1 (MYPT1). Furthermore, emodin in vivo inhibited acetylcholine-induced respiratory system resistance in mice. These results indicate that EEFS-induced relaxation results from emodin inhibiting LVDCC, SOCE, and Ca2+ sensitization. These findings suggest that Folium Sennae and emodin may be new sources of bronchodilators. This article is protected by copyright. All rights reserved.

5.
Theranostics ; 10(12): 5259-5275, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32373211

RESUMO

Purpose: Lacking effective targeted therapies, triple-negative breast cancer (TNBCs) is highly aggressive and metastatic disease, and remains clinically challenging breast cancer subtype to treat. Despite the survival dependency on the proteasome pathway genes, FDA-approved proteasome inhibitors induced minimal clinical response in breast cancer patients due to weak proteasome inhibition. Hence, developing effective targeted therapy using potent proteasome inhibitor is required. Methods: We evaluated anti-cancer activity of a potent proteasome inhibitor, marizomib, in vitro using breast cancer lines and in vivo using 4T1.2 murine syngeneic model, MDA-MB-231 xenografts, and patient-derived tumor xenografts. Global proteome profiling, western blots, and RT-qPCR were used to investigate the mechanism of action for marizomib. Effect of marizomib on lung and brain metastasis was evaluated using syngeneic 4T1BR4 murine TNBC model in vivo. Results: We show that marizomib inhibits multiple proteasome catalytic activities and induces a better anti-tumor response in TNBC cell lines and patient-derived xenografts alone and in combination with the standard-of-care chemotherapy. Mechanistically, we show that marizomib is a dual inhibitor of proteasome and oxidative phosphorylation (OXPHOS) in TNBCs. Marizomib reduces lung and brain metastases by reducing the number of circulating tumor cells and the expression of genes involved in the epithelial-to-mesenchymal transition. We demonstrate that marizomib-induced OXPHOS inhibition upregulates glycolysis to meet the energetic demands of TNBC cells and combined inhibition of glycolysis with marizomib leads to a synergistic anti-cancer activity. Conclusions: Our data provide a strong rationale for a clinical evaluation of marizomib in primary and metastatic TNBC patients.

7.
Int J Radiat Biol ; 96(6): 748-758, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32149567

RESUMO

Purpose: Simple, rapid and high-throughput dose assessment is critical for clinical diagnosis, treatment and emergency intervention in a large-scale radiological accident. The goal of this study is to screen and identify new ionizing radiation-responsive protein biomarkers in rat plasma.Materials and methods: Sprague-Dawley rats were exposed to single doses of 0, 1, 3, 5 Gy of Cobalt-60 γ-rays total body irradiation at a dose rate of 1 Gy/min. The tandem mass tag labeling (TMT) combined with liquid chromatography mass spectrometry (LC-MS/MS) approach was used to screen the differentially expressed proteins in rat plasma collected at 1, 3, 5 and 7 days post-irradiation. Bioinformatics analysis was conducted to explore the biological functions of these proteins. The expression levels of candidate radiation-sensitive protein biomarkers were confirmed using enzyme-linked immune-sorbent assay (ELISA).Results: A total of 503 differentially expressed proteins were identified. Most of these proteins were implicated in immune response, phagocytosis and signal transduction following ionizing radiation. Five up-regulated proteins including alpha-2-macroglobulin (A2m), chromogranin-A (CHGA), glutathione pertidase 3 (GPX3), clusterin (Clu) and ceruloplasmin (Cp) were selected for ELISA analysis. It was found that the expression levels of A2m, CHGA and GPX3 protein were increased in a dose-dependent manner at 1, 3 and 5 days after irradiation.Conclusion: Proteomics analysis revealed radiation-induced differentially expressed proteins in rat plasma. Our results suggested that A2m, CHGA, GPX3 protein expressions alterations in rat plasma may have potential as biomarkers to evaluate radiation exposure.

8.
Adv Mater ; : e1906432, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32134141

RESUMO

Delicate design of nanostructures for oxygen-evolution electrocatalysts is an important strategy for accelerating the reaction kinetics of water splitting. In this work, Ni-Fe layered-double-hydroxide (LDH) nanocages with tunable shells are synthesized via a facile one-pot self-templating method. The number of shells can be precisely controlled by regulating the template etching at the interface. Benefiting from the double-shelled structure with large electroactive surface area and optimized chemical composition, the hierarchical Ni-Fe LDH nanocages exhibit appealing electrocatalytic activity for the oxygen evolution reaction in alkaline electrolyte. Particularly, double-shelled Ni-Fe LDH nanocages can achieve a current density of 20 mA cm-2 at a low overpotential of 246 mV with excellent stability.

9.
Chemosphere ; 251: 126336, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32145574

RESUMO

1-Nitropyrene (1-NP) is a representative nitro-polycyclic aromatic hydrocarbon from diesel exhaust. Recently, we found that maternal 1-NP exposure caused fetal growth retardation and disturbed cognitive development in adolescent female offspring. To investigate long-term 1-NP exposure on spermatogenesis and steroidogenesis, male mice were exposed to 1-NP (1.0 mg/kg/day) by gavage for 70 days. There was no significant difference on relative testicular weight, number of testicular apoptotic cells and epididymal sperm count between 1-NP-exposed mice and controls. Although long-term 1-NP exposure did not influence number of Leydig cells, steroidogenic genes and enzymes, including STAR, P450scc, P45017α and 17ß-HD, were downregulated in 1-NP-expoed mouse testes. Correspondingly, serum and testicular testosterone (T) levels were reduced in 1-NP-exposed mice. Additional experiment showed that testicular GRP78 mRNA and protein were upregulated by 1-NP. Testicular phospho-IRE1α and sliced xbp-1 mRNA, a downstream molecule of IRE1α, were elevated in 1-NP-exposed mice. Testicular phospho-PERK and phospho-eIF2α, a downstream molecule of PERK pathway, were increased in 1-NP-exposed mice. Testicular NOX4, a subunit of NAPDH oxidase, and HO-1, MDA, two oxidative stress markers, were increased in 1-NP-exposed mice. Testicular GSH and GSH/GSSG were decreased in 1-NP-exposed mice. These results suggest that long-term 1-NP exposure induces reactive oxygen species-evoked ER stress and disrupts steroidogenesis in mouse testes.

10.
Sci Total Environ ; 722: 137811, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32179301

RESUMO

In this work, biochar based hydrogel microspheres were fabricated successfully to develop pH and ion strength dual-stimuli responsively controlled-release system for hydrophilic pesticide. Herein, gentian violet (GV) was selected as model hydrophilic pesticide. Taking advantage of the cross-linking reaction, GV was incorporated into biochar and the 3D network-structured hydrogel, guaranteeing a satisfying encapsulation efficiency and sustained release of pesticide. The leaching behavior of pesticide in simulated soil column at different pHs and ion strength was in accordance with the corresponding release performance, and bulk of pesticide was retarded on the surface. In addition, the pesticide carrier had nearly no toxic effect on the cell proliferation and zebrafish embryo, displaying a good biosafety. The work provides a promising strategy with a low-cost and simple procedure that could regulate pesticide release behavior, decrease leaching loss, and improve the utilization efficiency of pesticide.

11.
Environ Pollut ; 260: 113984, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32041019

RESUMO

1-nitropyrene (1-NP) is a key component of diesel exhaust-sourced fine particulate matter (PM2.5). Our recent study demonstrated that gestational 1-NP exposure caused placental proliferation inhibition and fetal intrauterine growth restriction (IUGR). This study aimed to investigate the role of genotoxic stress on 1-NP-induced placental proliferation inhibition and fetal IUGR. Human trophoblasts were exposed to 1-NP (10 µM). Growth index was reduced and PCNA was downregulated in 1-NP-exposed placental trophoblasts. More than 90% of 1-NP-exposed trophoblasts were arrested in either G0/G1 or G2/M phases. CDK1 and cyclin B, two G2/M cycle-related proteins, and CDK2, a G0/G1 cycle-related protein, were reduced in 1-NP-exposed trophoblasts. Phosphorylated Rb, a downstream molecule of CDK2, was inhibited in 1-NP-exposed trophoblasts. Moreover, DNA double-strand break was observed and γ-H2AX, another indicator of DNA double-strand break, was upregulated in 1-NP-exposed trophoblasts. Phosphorylated ATM, a key molecule of genotoxic stress, and its downstream molecule Chk2 were elevated. By contrast, Cdc25A, a downstream target of Chk2, was reduced in 1-NP-exposed trophoblasts. Phenyl-N-t-butylnitrone (PBN), a free radical scavenger, inhibited 1-NP-induced genotoxic stress and trophoblast cycle arrest. Animal experiment showed that N-acetylcysteine (NAC), an antioxidant, rescued 1-NP-induced placental proliferation inhibition and fetal IUGR in mice. These results provide evidence that reactive oxygen species (ROS)-mediated cellular genotoxic stress partially contributes to 1-NP-induced placental proliferation inhibition and fetal IUGR.

12.
Mol Ther Nucleic Acids ; 19: 937-950, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32004865

RESUMO

We previously found that cocaine abuse could increase microRNA134 (miR134) levels in the hippocampus; yet the roles of miR134 in cocaine-related abnormal psychiatric outcomes remain unknown. In this study, using the cocaine-induced conditioned place preference (CPP) mice model, we found that mice exhibit enhanced anxiety-like and depression-like behaviors during the cocaine extinction (CE) period of CPP, accompanied by obviously increased miR134 levels and decreased levels of 19 genes that are associated with synaptic plasticity, glia activity, and neurochemical microenvironments, in the ventral hippocampus (vHP). Knockdown of miR134 in vHP in vivo reversed the changes in 15 of 19 potential gene targets of miR134 and rescued the abnormal anxiety-like and depression-like behavioral outcomes in CE mice. In parallel, knockdown of miR134 reversed CE-induced changes in dendritic spines and synaptic proteins and increased the field excitatory postsynaptic potential (fEPSP) of CA1 pyramidal neurons in the vHP of CE mice. In addition, knockdown of miR134 suppressed the CE-enhanced microglia activity, inflammatory, apoptotic, and oxidative stress statuses in the vHP. With the data taken together, miR134 may be involved in cocaine-associated psychiatric problems, potentially via regulating the expressions of its gene targets that are related to synaptic plasticity and neurochemical microenvironments.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32027451

RESUMO

Photocatalysts with well-designed compositions and structures are desirable for achieving highly efficient solar-to-chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe2 TiO5 -TiO2 nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL-125(Ti) nanodisks (NDs) to Ti-Fe-O NCs, which are further converted to Fe2 TiO5 -TiO2 NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe2 TiO5 -TiO2 NCs show enhanced performance for PEC water oxidation compared with TiO2 NDs, Fe2 TiO5 nanoparticles (NPs) and Fe2 TiO5 -TiO2 NPs.

14.
Diabetes ; 69(4): 749-759, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31915154

RESUMO

Schwann cell-derived exosomes communicate with dorsal root ganglia (DRG) neurons. The current study investigated the therapeutic effect of exosomes derived from healthy Schwann cells (SC-Exos) on diabetic peripheral neuropathy (DPN). We found that intravenous administration of SC-Exos to type 2 diabetic db/db mice with peripheral neuropathy remarkably ameliorated DPN by improving sciatic nerve conduction velocity and increasing thermal and mechanical sensitivity. These functional improvements were associated with the augmentation of epidermal nerve fibers and remyelination of sciatic nerves. Quantitative RT-PCR and Western blot analysis of sciatic nerve tissues showed that SC-Exo treatment reversed diabetes-reduced mature form of miRNA (miR)-21, -27a, and -146a and diabetes-increased semaphorin 6A (SEMA6A); Ras homolog gene family, member A (RhoA); phosphatase and tensin homolog (PTEN); and nuclear factor-κB (NF-κB). In vitro data showed that SC-Exos promoted neurite outgrowth of diabetic DRG neurons and migration of Schwann cells challenged by high glucose. Collectively, these novel data provide evidence that SC-Exos have a therapeutic effect on DPN in mice and suggest that SC-Exo modulation of miRs contributes to this therapy.

15.
Clin Exp Rheumatol ; 38(1): 58-66, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31074719

RESUMO

OBJECTIVES: Regulatory T (Treg) cells are crucial players in the prevention of autoimmunity. Mechanistic target of rapamycin (mTOR) signalling negatively controls the development and function of Treg cells. The aim of the present study was to evaluate the effects of rapamycin, under the generic name sirolimus, on CD4+CD25+FoxP3+ Treg cells in rheumatoid arthritis (RA) patients with low disease activity or in DAS28 remission. METHODS: Fifty-five RA patients and 60 healthy controls were enrolled in this study. All patients had previously received conventional disease-modifying anti-rheumatic drugs (DMARDs) and were considered to have a low DAS28 score (≤3.2). Peripheral blood samples and clinical information were obtained at baseline and following 6 and 12 weeks of sirolimus treatment, or after 12 weeks of conventional treatment. Peripheral blood samples were also obtained from the healthy controls. The circulating levels of lymphocyte subpopulations were assessed by flow cytometry. RESULTS: Thirty-five patients received sirolimus and 20 patients continued treatment with conventional DMARDs. The absolute counts and proportions of CD4+CD25+FoxP3+ Treg cells were significantly lower in all RA patients with DAS28 ≤ 3.2 as compared with those in healthy controls. By contrast, the difference in circulating Th17 cell numbers was not significant. Sirolimus administration resulted in elevations in circulating Treg cell numbers and significant reductions in the Th17/Treg cell ratio, whereas the circulating level of Treg cells and the Th17/Treg cell ratio in patients under conventional treatment both showed a tendency of reduction. Furthermore, a greater proportion of patients under sirolimus treatment achieved DAS28-based remission at 12 weeks. CONCLUSIONS: Sirolimus can favourably expand Treg cells in RA patients with DAS28 ≤3.2, consequently restoring a healthy balance of Th17/Treg cells, which might improve the likelihood of long-term and sustained clinical remission and reduce the probability of disease flare-ups in RA.

16.
Chemosphere ; 242: 125203, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31678848

RESUMO

Insect glutathione S-transferases (GSTs) are important in insecticide detoxification and Insect-specific GSTs, Epsilon and Delta, have largely expanded in insects. In this study, we functionally expressed and characterized an epsilon class GST gene (BdGSTe8), predominant in the adult Malpighian tubules of Bactrocera dorsalis. This gene may be associated with malathion resistance based on transcriptional studies of resistant and susceptible strains. RNA interference-mediated knockdown of this gene significantly recovered malathion susceptibility in the adults of a malathion-resistant strain, and overexpression of BdGSTe8 enhanced resistance in transgenic Drosophila. Analysis of BdGSTe8 polymorphism showed that several point mutations may be associated with metabolic resistance to malathion. A cytotoxicity assay in Escherichia coli indicated that both of the recombinant BdGSTe8 proteins may play a functional role in protecting cells from toxicity. The allele of BdGSTe8-B conferred higher levels of malathion detoxification capability. Liquid chromatography and ultra-performance liquid chromatography-tandem mass spectrometry analysis showed that the BdGSTe8-A allele did not metabolize malathion directly. However, the BdGSTe8-B allele was involved in the direct metabolism of malathion, which was caused by a mutation in V128A. Further analysis of the sequence suggests that BdGSTe8 evolved rapidly. It maybe play the role of a backup gene and could become a new gene in the future in order to retain the ability of detoxification of malathion, which was driven by positive selection. These results suggest that divergent molecular evolution in BdGSTe8 has played a role in metabolic resistance to malathion in B. dorsalis.

17.
Chemosphere ; 243: 125356, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31743867

RESUMO

1-nitropyrene (1-NP) is widespread in the environment, as a typical nitrated polycyclic aromatic hydrocarbon. The purpose of this research was to explore the effects of gestational 1-NP exposure on susceptibility of allergic asthma in offspring. Maternal mice were exposed to 1-NP (100 µg kg-1) by gavage throughout the whole pregnancy. Pups were sensitized by injecting with ovalbumin (OVA) on postnatal day (PND)23, 29, and 36, respectively. At 7 days following the last injection, sensitized mice were exposed to aerosol OVA. As expected, there were quite a few inflammatory cells in the lungs of OVA-sensitized pups, accompanied by bronchial wall thickening and hyperemia. Elevated goblet cells and overproduced mucus were observed in the airways of OVA-sensitized pups. Interestingly, gestational 1-NP exposure aggravated infiltration of inflammatory cells, mainly eosinophils, in OVA-sensitized offspring. Although it had little effect on airway smooth muscle layer thickening and basement membrane fibrosis, gestational 1-NP exposure aggravated goblet cell hyperplasia, Muc5ac mRNA upregulation, and mucus secretion in the airways of OVA-sensitized and challenged offspring. Mechanistically, gestational 1-NP exposure aggravated elevation of pulmonary IL-5 in OVA-sensitized pups. These findings suggest that gestational 1-NP exposure increases susceptibility of allergic asthma in offspring.

18.
Org Lett ; 21(24): 10069-10074, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31814413

RESUMO

A vinylogous addition-cyclization reaction of cyclic α-amide enones with good yields and excellent regioselectivity catalyzed by cinchona squaramides has been reported. Using 4-aryl-3-butenyl N-acylpyrazoles as nucleophiles led to 1,4-selective γ-addition of enones, and 1,2-selective γ-addition of enones took place when 3-aryl-3-butenyl N-acylpyrazoles was used as the donors. The 1,4- and 1,2-selective γ-adducts are then formed into the corresponding highly stereoselective and enantioselective fused bicyclic and spirocyclic products by intramolecular cyclization. The synthetic utility of the products has also been demonstrated through further transformations of the products.

19.
Inflammation ; 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31828589

RESUMO

Sepsis or septic shock is often accompanied by organ dysfunction, among which acute kidney injury (AKI) is the most frequent event that appears early during sepsis. To harness urinary metabolic profiling to discover potential biomarkers of septic acute kidney injury in pediatric patients at intensive care units, we collected urine samples from 27 septic children with AKI and 30 septic children without AKI. We used ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) for profiling and multiple regression analysis to explore the potential biomarkers of sepsis with AKI. We identified a clear distinction in the UPLC-QTOF/MS results for septic children with and without AKI after the development of sepsis, specifically 18 and 17 metabolites with different levels at 12 and 24 h, respectively. Metabolic pathways associated with septic AKI included lipid metabolism, particularly processes involving glycerophospholipid metabolism. L-Histidine, DL-indole-3-lactic acid, trimethylamine N-oxide, and caprylic acid were uncovered as potential biomarkers of septic AKI at 12 h, while gentisaldehyde, 3-ureidopropionate, N4-acetylcytidine, and 3-methoxy-4-hydroxyphenylglycol sulfate were identified as potential candidates at 24 h. We further found that combinations of metabolites were more effective diagnostic marker compared with individual metabolites, with an area under the receiver operating characteristics curve of 0.905 and 0.97 at 12 and 24 h, respectively. Our results indicated that metabolomic analysis could be a promising approach for identifying diagnostic biomarkers of pediatric septic AKI and helped elucidate the pathological mechanisms involved.

20.
Huan Jing Ke Xue ; 40(10): 4562-4568, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854824

RESUMO

Nitrogen removal in constructed wetlands (CWs) is highly affected by the supply of organic carbon. Thus, to enhance nitrogen removal in the horizontal subsurface flow of CWs, plant carbon sources were added during the downstream portion of the wetland. Moreover, the characteristics of static release and the denitrification potential of Typha were evaluated using three different pretreatment methods (i.e., minced, acid-heated, and alkali-heated). The average concentrations of COD released and the nitrate removal rate with the alkali-heated, acid-heated, and minced Typha were 89.57 mg·L-1 and 75.2%, 67.27 mg·L-1 and 67.2%, and 54.45 mg·L-1 and 23.5%, respectively. The results showed that different pretreatment methods resulted in the release of different amounts of acetic acid, and the alkali-heated Typha performed much better than the other pretreatments. Therefore, the alkali-heated Typha was selected and added to the middle of the horizontal subsurface flow CW, which improved the nitrogen-removal rate significantly; the average removal rate of TN and TP was higher than that of a control CW by 30.3% and 33.9%, respectively. However, the COD concentration of the CW with the alkali-heated Typha was not significantly increased.


Assuntos
Desnitrificação , Typhaceae , Áreas Alagadas , Nitratos , Nitrogênio , Eliminação de Resíduos Líquidos
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