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2.
Huan Jing Ke Xue ; 39(6): 2904-2910, 2018 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965649

RESUMO

Constructed wetlands (CWs) have high potential for wastewater treatment in developing countries because of their operational convenience and low maintenance costs. However, rapid accumulation of macrophytes in these wetlands, as a result of plant litter recycling, can lead to lower removal efficiencies. Periodic harvesting is consider to be the effective measure to maintain the wastewater treatment performance, and so a lot of harvested plant waste needs to be properly disposed of. However, in China, plant waste is usually used for agricultural burning and the greenhouse gas emissions bring adverse effects on the atmospheric environment. In the traditional subsurface flow CW, the dissolved oxygen (DO) concentration is low, resulting in long-term anoxic or anaerobic conditions, which will bring damages to plant body, such as membrane lipid peroxidation and protein and DNA damage. Generally, the addition of biochar to CWs is beneficial for aeration, and improves the internal environment of wetlands. Hence, the effects of plant biochar on the pollutant purification efficiencies in CWs were studied, and the role of biochar in macrophyte growth and antioxidative response was investigated. Based on the results of biochar application in agricultural fields, the harvested wetland plant straw was pyrolyzed to biochar at 500 ℃ under a dynamic high-purity nitrogen atmosphere. The wetland plant Acorus calamus L. (AC) was chosen for this study. The impact characteristics of biochar on AC were studied in five independent CWs built in a greenhouse, by combining the analyses of growth and antioxidative responses of plants. Results showed that the removals of ammonium (NH4+-N) and total nitrogen (TN) were significantly enhanced when biochar was added to CWs and that higher long-term nitrogen removal rates were achieved when the biochar application rate was increased. The photosynthetic pigment content in AC increased significantly with increasing biochar application rate. This stimulated photosynthesis and increased the soluble protein (SP) and plant biomass amounts. Further, glutamine synthetase (GS) activity was strengthened with the addition of biochar. This helped enhance the NH4+-N metabolism and increased the relative uptake rate of AC. This study confirmed that long-term anoxic or anaerobic conditions in CWs cause membrane lipid oxidation in plants. However, the activity of the antioxidative response system was promoted with the addition of biochar, significantly decreasing the malonic dialdehyde (MDA) content in the plants.


Assuntos
Acorus/crescimento & desenvolvimento , Carvão Vegetal/química , Eliminação de Resíduos Líquidos , Purificação da Água , Áreas Alagadas , Amônia/metabolismo , Antioxidantes , China , Nitrogênio/metabolismo , Águas Residuárias
3.
Zookeys ; (754): 127-139, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755260

RESUMO

In the present study, the complete mitogenome of Theretra japonica was sequenced and compared with other sequenced mitogenomes of Sphingidae species. The mitogenome of T. japonica, containing 37 genes (13 protein-coding genes, 22 tRNA genes, and two rRNA genes) and a region rich in adenine and thymine (AT-rich region), is a circular molecule with 15,399 base pairs (bp) in length. The order and orientation of the genes in the mitogenome are similar to those of other sequenced mitogenomes of Sphingidae species. All 13 protein-coding genes (PCGs) are initiated by ATN codons except for the cytochrome C oxidase subunit 1 gene (cox1) which is initiated by the codon CGA as observed in other lepidopteran insects. Cytochrome C oxidase subunit 2 gene (cox2) has the incomplete termination codon T and NADH dehydrogenase subunit 1 gene (nad1) terminates with TAG while the remainder terminates with TAA. Additionally, the codon distributions of the 13 PCGs revealed that Ile and Leu2 are the most frequently used codon families and codons CGG, CGC, CCG, CAG, and AGG are absent. The 431 bp AT-rich region includes the motif ATAGA followed by a 23 bp poly-T stretch, short tandem repeats (STRs) of TC and TA, two copies of a 28 bp repeat 'ATTAAATTAATAAATTAA TATATTAATA' and a poly-A element. Phylogenetic analyses within Sphingidae confirmed that T. japonica belongs to the Macroglossinae and showed that the phylogenetic relationship of T. japonica is closer to Ampelophaga rubiginosa than Daphnis nerii. Phylogenetic analyses within Theretra demonstrate that T. japonica, T. jugurtha, T. suffusa, and T. capensis are clustered into one clade.

4.
Cytotechnology ; 69(6): 875-883, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28540540

RESUMO

Bombyx batryticatus is a traditional Chinese medicine. To understand apoptotic effect of B. batryticatus ethanol extract (BBE), we investigated the role of BBE in inducing apoptosis of human gastric cancer cells SGC-7901. Cells treated with BBE and apoptosis was assessed by methyl thiazolyl tetrazolium (MTT) assay, morphological changes, DNA fragmentation and flow cytometry assays. The expression of Bcl-2, Bax and P21 were evaluated by western blot analysis and real time polymerase chain reaction. MTT assay showed that the cytotoxicity of BBE extract on SGC-7901 cells was correlated with treatment time and concentration. After treatment with 6 mg/mL of BBE the microscopy showed that, the majority of SGC-7901 cells were obviously reduced, distorted and grew slowly. Annexin-V/propidium iodide double-staining assay emerge the early apoptosis and the late apoptosis after treatment with different times by laser confocal fluorescence microscopy and flow cytometer. Cell cycle analysis of SGC 79 cells showed that BBE induced cell cycle arrest in the G1 and G2 phases. DNA fragmentation indicated the trend of BBE inducing apoptosis on SGC-7901 cells. The qRT-PCR and western blot analysis indicated that the mRNA and protein expressions of Bax and P21 were significantly up-regulated whereas that of Bc1-2 was down-regulated after treatment with BBE for 24 h. Our results revealed a correlation between gene regulation and BBE-induced apoptosis, which might indicate the potential of BBE in cancer therapy.

5.
J Colloid Interface Sci ; 329(1): 48-53, 2009 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-18922543

RESUMO

High molecular weight powdery polyacrylonitrile (PAN) polymers were prepared by aqueous suspension polymerization employing itaconic acid (IA) as comonomer and alpha,alpha(')-azobisisobutyronitrile (AIBN) as initiator at 60 degrees C. PAN polymers obtained with different monomer ratios were characterized by EA, DSC, FTIR and XRD. It is investigated that the oxygen element content in PAN polymers increased with the increase of required IA amounts in the feed and heat-treatment temperatures. DSC curves of PAN copolymers exhibited the triplet character, owing to the exothermic cyclization and oxidative reactions during heat-treatment process. Introduction of IA in the feed relaxed exothermic reactions of PAN polymers under air atmosphere. Structure and crystallinity changes were affected by required IA amounts in the feed and enhancement of heat-treatment temperatures. The characteristic functional groups (including C[triple bond]N, C=O, CH(2)) presented in FTIR spectra of PAN polymers indicated copolymerization reaction of AN and IA. Existence of some organic groups (C-O, C=C and/or C=N) indicated formation of ladderlike structure during heat-treatment process. PAN homopolymer had the better crystallinity (mainly peak intensity and peak area around 2theta = 17 degrees) than most RT-PAN copolymers. When heat-treatment temperature is around 210 degrees C, peak intensity, peak area, L(c) and CI of HT-PAN polymers corresponding to samples 1# and 2# got maxima, while crystallinity became weak at higher heat-treatment temperatures.

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