RESUMO
Thallium (Tl) as a prominent priority contaminant in aquatic environment necessitates rigorous regulation. However, limited horizon devotes the impact of selective oxidation on the process of thallium purification. In this study, selective active radical of singlet oxygen (1O2) was continually generated for Tl(â ) oxidation accomplished with efficient Tl(â ¢) immobilization using iron-driven copper oxide (CuFe)/peroxymonosulfate (PMS). Fe-doping changed the active center of electronic structure for enhancing the catalytic and adsorptive reactivities, and installed magnetism for solid-liquid separation. Rapid reaction rate (0.253 min-1) coupled with vigorous elimination efficiency (98.32%) relied on electrostatic attraction, surface complexation, and H-bond interaction. EPR and XPS analyses demonstrated that the synergistic effects of ≡ Cu(â )/≡Cu(â ¡) and ≡ Fe(â ¢)/≡Fe(â ¡) redounded to the sustained generation of 1O2 through the pathway of PMS â â¢O2- â 1O2, and 1O2 exploited an advantage to selectively oxidize Tl(â ) to Tl(â ¢). 3D isosurface cubic charts revealed that the immobilizing ability of Tl(â ¢) hydrate for CuFe was notably superior to that of Tl(â ¢) hydrate for CuO and Tl(â ) hydrate for CuO/CuFe, which further attested surface reactivity promoted stable immobilization form. This work develops the continuous generation of 1O2 and stable immobilization with the goal of efficiently cleansing Tl-containing wastewater.
Assuntos
Ferro , Oxigênio Singlete , Tálio , Tálio/química , Ferro/química , Oxigênio Singlete/química , Oxirredução , Cobre/química , CatáliseRESUMO
Maize (Zea mays) cultivation is strongly affected by both abiotic and biotic stress, leading to reduced growth and productivity. It has recently become clear that regulators of plant stress responses, including the phytohormones abscisic acid (ABA), ethylene (ET), and jasmonic acid (JA), together with reactive oxygen species (ROS), shape plant growth and development. Beyond their well established functions in stress responses, these molecules play crucial roles in balancing growth and defense, which must be finely tuned to achieve high yields in crops while maintaining some level of defense. In this review, we provide an in-depth analysis of recent research on the developmental functions of stress regulators, focusing specifically on maize. By unraveling the contributions of these regulators to maize development, we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.
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Proteínas de Plantas , Zea mays , Zea mays/metabolismo , Proteínas de Plantas/metabolismo , Reguladores de Crescimento de Plantas , Ácido Abscísico , Plantas/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
BACKGROUND: Seed size is an important factor contributing to maize yield, but its molecular mechanism remains unclear. The seed coat, which serves as one of the three components of the maize grain, determines seed size to a certain extent. The seed coat also shares the maternal genotype and is an ideal material for studying heterosis. RESULTS: In this study, the self-pollinated seeds of the maize hybrid Yudan888 and its parental lines were continuously collected from 0 day after pollination (DAP) to 15 DAP for phenotyping, cytological observation and RNA-seq. The phenotypic data showed that 3 DAP and 8 DAP are the best time points to study maize seed coat heterosis. Cytological observations indicated that maize seed coat heterosis might be the result of the coordination between cell number and cell size. Furthermore, the RNA-seq results showed that the nonadditive genes changed significantly between 3 and 8 DAP. However, the number of genes expressed additively was not significantly different. Our findings suggest that seed coat heterosis in hybrid is the result of nonadditive expression caused by dynamic changes in genes at different time points during seed expansion and seed coat development. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment indicated that genes related to DNA replication, cell cycle regulation, circadian rhythms and metabolite accumulation contributed significantly to hybrid seed coat heterosis. CONCLUSION: Maize seed coat phenotyping allowed us to infer that 3 DAP and 8 DAP are important time points in the study of seed coat heterosis. Our findings provide evidence for genes involved in DNA replication, cell cycle regulation, circadian rhythms and metabolite accumulation in hybrid with high or low parental expression as major contributors to hybrid seed coat heterosis.
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Vigor Híbrido , Zea mays , Zea mays/genética , Sementes/genética , Genótipo , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hibridização GenéticaRESUMO
Maize has become one of the most widely grown grains in the world, and the stay-green mutant allows these plants to maintain their green leaves and photosynthetic potential for longer following anthesis than in non-mutated plants. As a result, stay-green plants have a higher production rate than non-stay-green varieties due to their prolonged grain-filling period. In this study, the candidate genes related to the visual stay-green at the maturation stage of maize were investigated. The F2 population was derived from the T01 (stay-green) and the Xin3 (non-stay-green) cross. Two bulked segregant analysis pools were constructed. According to the method of combining ED (Euclidean distance), Ridit (relative to an identified distribution unit), SmoothG, and SNP algorithms, a region containing 778 genes on chromosome 9 was recognized as the candidate region associated with the visual stay-green in maize. A total of eight modules were identified using WGCNA (weighted correlation network analysis), of which green, brown, pink, and salmon modules were significantly correlated with visual stay-green. BSA, combined with the annotation function, discovered 7 potential candidate genes, while WGCNA discovered 11 stay-green potential candidate genes. The candidate range was further reduced due through association analysis of BSA-seq and RNA-seq. We identified Zm00001eb378880, Zm00001eb383680, and Zm00001eb384100 to be the most likely candidate genes. Our results provide valuable insights into this new germplasm resource with reference to increasing the yield for maize.
Assuntos
Grão Comestível , Zea mays , RNA-Seq , Mapeamento Cromossômico , Zea mays/genética , Grão Comestível/genéticaRESUMO
To explore the application of biosensor in real-time monitoring of composite heavy metal polluted wastewater in view of the low performance of MFC sensor, this study used sodium alginate to immobilize biochar to the anode of MFC biosensor, and conducted a study on the sensor performance and related biological processes. The results showed that under the optimal HRT conditions, the output power of the MFC-sensor (BC-300) was 0.432 W/m3 after biochar modification, which was much higher than the highest power density of CG and BC-0 of 0.117 and 0.088 W/m3. The correlation coefficient was greater than that of the control group at the plating wastewater concentration of 0.1-1.0 M and had a wider detection range, and the time to recover the output voltage was 1/3 of that of the control group. The biochar significantly promoted the sensitivity, interference resistance, recovery and anti-interference performance of the MFC-sensor. The intrinsic mechanism was that the composition and structure of biochar lead to a 1.53 fold increase in the abundance of electrogenic microorganisms and the abundance of functional genes such as cytochrome c (MtrABC, CymA, Cox, etc.) and flavin (riba, Rib B, gdh, ushA, IDH, etc.) increased by about 1.03-3.20 times, which promoted the shift of electrons from intracellular to extracellular receptors and significantly improved the electron transfer and the energy metabolism efficiency. The results of this study can provide a reference for the application of MFCsensor to the detection of complex heavy metal effluents.
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Fontes de Energia Bioelétrica , Metais Pesados , Transporte de Elétrons , Elétrons , Águas Residuárias , Eletrodos , EletricidadeRESUMO
It is very important to control methane emissions to reduce global warming. In this study, a new attempt of one oxidant (potassium peroxymonosulfate (PMS)) was made to adjust the oxidation-reduction potential (Eh) by adding different mass of (0 g, 31.25 g, 62.5 g, 125 g, 250 g and 500 g) for the reduction of methane emissions from integrated vertical-flow constructed wetland (IVCW), where the IVCW system has been divided into the root-water system and the stem-leaf system of methane emissions. Results show that the reduced CH4 emission from IVCW was the highest with decreased by 43.5% compared to blank group (PMS = 0), when adding 125 g PMS. Importantly, the reduced CH4 from the root-water system of IVCW was higher than that of the stem-leaf system of IVCW, when adding PMS. It's found that Eh not only has a significant correlation with CH4 flux, but also has a significant relationship between PMS quality, DO, water temperature and sampling time (yEh = -0.44XPMS + 6.82XDO + 0.38t - 264.1, R2 = 0.99). It concludes that PMS, as an oxidant, is a very feasible method for controlling methane emissions from IVCW. It's concluded from this study that it is a feasible engineering method by using PMS as an oxidant for reducing methane emissions from IVCWs when treating artificial domestic sewage. Further research may combine other methods together such as microbiology, physical control and hydrology control for mitigating the CH4 emissions from constructed wetlands for more types of wastewater.
Assuntos
Metano , Áreas Alagadas , Oxidantes , Água , Dióxido de CarbonoRESUMO
Riparian buffers benefit both natural and man-made ecosystems by preventing soil erosion, retaining soil nutrients, and filtering pollutants. Nevertheless, the relationship between vertical methane fluxes, soil carbon, and methane microbial communities in riparian buffers remains unclear. This study examined vertical methane fluxes, soil carbon, and methane microbial communities in three different soil depths (0-5 cm, 5-10 cm, and 10-15 cm) within a riparian buffer of a Sponge City Park for one year. Structural equation model (SEM) results demonstrated that vertical methane fluxes varied with soil depths (λ = -0.37) and were primarily regulated by methanogenic community structure (λ = 0.78). Notably, mathematical regression results proposed that mcrA/pmoA ratio (R2 = 0.8) and methanogenic alpha diversity/methanotrophic alpha diversity ratio (R2 = 0.8) could serve as valid predictors of vertical variation in methane fluxes in the riparian buffer of urban river. These findings suggest that vertical variation of methane fluxes in riparian buffer soils is mainly influenced by carbon inputs and methane microbial abundance and community diversity. The study's results quantitatively the relationship between methane fluxes in riparian buffer soils and abiotic and biotic factors in the vertical direction, therefore contributing to the further development of mathematical models of soil methane emissions.
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Euryarchaeota , Microbiota , Humanos , Solo/química , Metano , Carbono , Microbiologia do SoloRESUMO
This study compared the changes in chemical components during the processing of different types of Aconiti Lateralis Radix Praeparata(ALRP) in "Jianchang" faction, i.e., dried ginger-steamed ALRP pieces(Yin-FP), sand-fried ALRP pieces(Yang-FP), and rice swill water-bleached ALRP pieces(DFP), and provided a scientific basis for the mechanism in toxicity reduction and efficacy enhancement from a compositional perspective. Samples were collected during the processing of the three types of ALRP pieces, yielding raw ALRP pieces, water-bleached Yin-FP, ginger juice-moistened Yin-FP, steamed Yin-FP, water-bleached Yang-FP, sand-fried Yang-FP, water-bleached DFP, rice swill water-bleached DFP, and roasted DFP. Aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine, benzoylhypaconine, aconine, mesaconine, hypaconine, salsolinol, fuziline, and higenamine in the extracts were determined by UPLC-MS/MS, and then content analysis and cluster heatmap analysis were performed on 11 sets of samples. During the processing of the three types of ALRP pieces, bleaching significantly reduced the content of 12 alkaloids; steaming, stir-frying, and roasting significantly reduced the content of diester-type alkaloids(aconitine, mesaconitine, and hypaconitine) and significantly increased the content of monoester-type alkaloids(benzoylaconine, benzoylmesaconine, and benzoylhypaconine) and aminoalcohol-type alkaloids(aconine, mesaconine, and hypaconine). During the processing of Yin-FP, the diester-type alkaloids continuously decreased, while the monoester-type and aminoalcohol-type alkaloids showed an initial decrease followed by an increase. During the processing of Yin-FP, Yang-FP, and DFP, the diester-type alkaloids continuously decreased, while the monoester-type and aminoalcohol-type alkaloids showed an initial decrease followed by an increase. Steamed Yin-FP showed a higher increase in content than fried Yang-FP and roasted DFP. Comprehensive analysis of content differences in toxic and therapeutic components in three ALRP pieces suggests that the distinctive processing methods in "Jianchang" faction can indeed achieve detoxification and efficacy enhancement on ALRP. This study provides references for understanding the mechanisms of action of the three processing methods.
Assuntos
Alcaloides , Medicamentos de Ervas Chinesas , Oryza , Zingiber officinale , Aconitina/análise , Espectrometria de Massas em Tandem , Areia , Espectrometria de Massa com Cromatografia Líquida , Cromatografia Líquida , Medicamentos de Ervas Chinesas/química , Cromatografia Líquida de Alta Pressão/métodos , Alcaloides/análise , VaporRESUMO
Myocardial fibrosis predisposes the development of main adverse cardiovascular events (MACEs) in various cardiac disorders. Native T1 derived from cardiac magnetic resonance allows the quantitative assessment of myocardial fibrosis without the use of contrast media. However, the prognostic value of native T1 in risk stratification remains uncertain. We searched MEDLINE®, Embase, and the Cochrane Library for cohort studies up to July 31, 2021, that reported prognostic data for native T1 in various cardiac disorders; the studies enrolling patients with myocardial iron or amyloid deposition, edema, and inflammation were excluded. A random effects meta-analysis was conducted. Heterogeneity was assessed using I2 statistic. Nineteen studies with 5,380 patients were included in this meta-analysis. Patients with MACEs had higher native T1 than those without [weighted mean difference: 27.35 (15.55-39.16), I2 = 23.2%]. The increase of native T1 per 1 ms [pooled adjusted hazard ratio (HR): 1.02 (1.00-1.03), I2 = 41.8%] and per ≥ 10 ms [pooled adjusted HR: 1.11 (1.07-1.16), I2 = 28.6%] was both associated with the development of MACEs; the categorical variable derived from native T1 also has the predicative value for MACEs [pooled adjusted HR: 5.97 (3.69-9.68), I2 = 0.0%].Myocardial native T1 potentially serves as a prognostic biomarker in patients with various cardiac disorders. Different variable definitions of native T1 have different positively predictive value for outcome; the categorical variable derived from native T1 may be more helpful in identifying high-risk patients.
Assuntos
Cardiomiopatias , Doenças Cardiovasculares , Cardiomiopatias/patologia , Meios de Contraste , Fibrose , Humanos , Imagem Cinética por Ressonância Magnética , Miocárdio/patologia , Valor Preditivo dos Testes , PrognósticoRESUMO
OBJECTIVES: To develop and validate radiomic models for preoperative prediction of intraductal component in invasive breast cancer (IBC-IC) using the intratumoral and peritumoral features derived from dynamic contrast-enhanced MRI (DCE-MRI). METHODS: The prediction models were developed in a primary cohort of 183 consecutive patients from September 2017 to December 2018, consisting of 45 IBC-IC and 138 invasive breast cancers (IBC). The validation cohort of 111 patients (27 IBC-IC and 84 IBC) from February 2019 to January 2020 was enrolled to test the prediction models. A total of 208 radiomic features were extracted from the intratumoral and peritumoral regions of MRI-visible tumors. Then the radiomic features were selected and combined with clinical characteristics to construct predicting models using the least absolute shrinkage and selection operator. The area under the curve (AUC) of receiver operating characteristic, sensitivity, and specificity were used to evaluate the performance of radiomic models. RESULTS: Four radiomic models for prediction of IBC-IC were built including intratumoral radiomic signature, peritumoral radiomic signature, peritumoral radiomic nomogram, and combined intratumoral and peritumoral radiomic signature. The combined intratumoral and peritumoral radiomic signature had the optimal diagnostic performance, with the AUC, sensitivity, and specificity of 0.821 (0.758-0.874), 0.822 (0.680-0.920), and 0.739 (0.658-0.810) in the primary cohort and 0.815 (0.730-0.882), 0.778 (0.577-0.914), and 0.738 (0.631-0.828) in the validation cohort. CONCLUSIONS: The radiomic model based on the combined intratumoral and peritumoral features from DCE-MRI showed a good ability to preoperatively predict IBC-IC, which might facilitate the individualized surgical planning for patients with breast cancer before breast-conserving surgery. KEY POINTS: ⢷Preoperative prediction of intraductal component in invasive breast cancer is crucial for breast-conserving surgery planning. ⢠Peritumoral radiomic features of invasive breast cancer contain useful information to predict intraductal components. ⢷Radiomics is a promising non-invasive method to facilitate individualized surgical planning for patients with breast cancer before breast-conserving surgery.
Assuntos
Neoplasias da Mama , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Nomogramas , Curva ROC , Estudos RetrospectivosRESUMO
BACKGROUND: Non-invasive modalities for assessing axillary lymph node (ALN) are needed in clinical practice. PURPOSE: To investigate the suspicious ALN on unenhanced T2-weighted (T2W) imaging and intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) for predicting ALN metastases (ALNM) in patients with T1-T2 stage breast cancer and clinically negative ALN. MATERIAL AND METHODS: Two radiologists identified the most suspicious ALN or the largest ALN in negative axilla by T2W imaging features, including short axis (Size-S), long axis (Size-L)/S ratio, fatty hilum, margin, and signal intensity on T2W imaging. The IVIM parameters of these selected ALNs were also obtained. The Mann-Whitney U test or t-test was used to compare the metastatic and non-metastatic ALN groups. Finally, logistic regression analysis with T2W imaging and IVIM features for predicting ALNM was conducted. RESULTS: This study included 49 patients with metastatic ALNs and 50 patients with non-metastatic ALNs. Using the above conventional features on T2W imaging, the sensitivity and specificity in predicting ALNM were not high. Compared with non-metastatic ALNs, metastatic ALNs had lower pseudo-diffusion coefficient (D*) (P = 0.043). Logistic regression analysis showed that the most useful features for predicting ALNM were signal intensity and D*. The sensitivity and specificity predicting ALNM that satisfied abnormal signal intensity and lower D* were 73.5% and 84%, respectively. CONCLUSIONS: The abnormal signal intensity on T2W imaging and one IVIM feature (D*) were significantly associated with ALNM, with sensitivity of 73.5% and specificity of 84%.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Metástase Linfática/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Axila , Mama/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Linfonodos/diagnóstico por imagem , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Cold limits the growth and yield of maize in temperate regions, but the molecular mechanism of cold adaptation remains largely unexplored in maize. To identify early molecular events during cold shock, maize seedlings were treated under 4 °C for 30 min and 2 h, and analyzed at both the proteome and phosphoproteome levels. Over 8500 proteins and 19,300 phosphopeptides were quantified. About 660 and 620 proteins were cold responsive at protein abundance or site-specific phosphorylation levels, but only 65 proteins were shared between them. Functional enrichment analysis of cold-responsive proteins and phosphoproteins revealed that early cold response in maize is associated with photosynthesis light reaction, spliceosome, endocytosis, and defense response, consistent with similar studies in Arabidopsis. Thirty-two photosynthesis proteins were down-regulated at protein levels, and 48 spliceosome proteins were altered at site-specific phosphorylation levels. Thirty-one kinases and 33 transcriptional factors were cold responsive at protein, phosphopeptide, or site-specific phosphorylation levels. Our results showed that maize seedlings respond to cold shock rapidly, at both the proteome and phosphoproteome levels. This study provides a comprehensive landscape at the cold-responsive proteome and phosphoproteome in maize seedlings that can be a significant resource to understand how C4 plants respond to a sudden temperature drop.
Assuntos
Arabidopsis , Proteoma , Arabidopsis/metabolismo , Temperatura Baixa , Fosfopeptídeos/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Plântula/metabolismo , Zea mays/genética , Zea mays/metabolismoRESUMO
Increased agricultural surface runoff in rural watersheds is a leading cause of nonpoint source pollution. In this study, a new biomass concentrator reactor (BCR) is conducted to degrade simulated agricultural surface runoff for both start-up process and treatment process. The results show that both in the start-up phase and in the stable phase, BCR had a good degradation effect on simulated agricultural surface runoff. Within 13 days-15 days of completed start-up of BCR, degradation of COD can be considered to the first-order kinetics: lnCt=lnC0-0.1377t (R2 = 0.78). During the stabilization phase, the average removal rate of COD, NH4+-N, NO3--N, TN and TP from the effluents through the BCR membrane was 94.58%, 85.79%, 53.58%, 37.87%, and 60.62%, respectively, which was increased by 7.4%, 2.5%, 5.1%, 0.18% and 11.4%, respectively, compared to control experiment which the effluents without membrane. The pollutants degradation by BCR in stable phase show a partly relative model of Lawrence-McCarty equation, which the nitrogen and phosphorus degradation is vN=(4.1+S)/(2.53×S) (R2 = 0.69) and vP=(8.78+S)/(3.0×S) (R2 = 0.67), respectively. In the stable phase, the operation cost of BCR is about $0.08/(Lâ¢d). Future research on improved BCR maybe focus on the membrane pollution and cleaning, optimized operation conditions, new materials of membrane.
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Movimentos da Água , Poluentes Químicos da Água , Biomassa , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise , Poluição da ÁguaRESUMO
Metabolites are the intermediate and final products of metabolism, which play essential roles in plant growth, evolution and adaptation to changing climates. However, it is unclear how evolution contributes to metabolic variation in plants. Here, we investigated the metabolomics data from leaf and seed tissues in maize and rice. Using principal components analysis based on leaf metabolites but not seed metabolites, metabolomics data could be clearly separated for rice Indica and Japonica accessions, while two maize subgroups, temperate and tropical, showed more visible admixture. Rice and maize seed exhibited significant interspecific differences in metabolic variation, while within rice, leaf and seed displayed similar metabolic variations. Among 10 metabolic categories, flavonoids had higher variation in maize than rice, indicating flavonoids are a key constituent of interspecific metabolic divergence. Interestingly, metabolic regulation was also found to be reshaped dramatically from positive to negative correlations, indicative of the differential evolutionary processes in maize and rice. Moreover, perhaps due to this divergence significantly more metabolic interactions were identified in rice than maize. Furthermore, in rice, the leaf was found to harbor much more intense metabolic interactions than the seed. Our result suggests that metabolomes are valuable for tracking evolutionary history, thereby complementing and extending genomic insights concerning which features are responsible for interspecific differentiation in maize and rice.
Assuntos
Metabolômica , Oryza/metabolismo , Zea mays/metabolismo , Evolução Molecular , Variação Genética , Genética Populacional , Metabolômica/métodos , Oryza/genética , Folhas de Planta/metabolismo , Análise de Componente Principal , Sementes/metabolismo , Zea mays/genéticaRESUMO
Temperature is a major factor regulating plant growth. To reproduce at extreme temperatures, plants must develop normal reproductive organs when exposed to temperature changes. However, little is known about the underlying molecular mechanisms. Here, we identified the maize (Zea mays) mutant thermosensitive vanishing tassel1-R (tvt1-R), which lacks tassels at high (restrictive) temperatures due to shoot apical meristem (SAM) arrest, but forms normal tassels at moderate (permissive) temperatures. The critical stage for phenotypic conversion in tvt1-R mutants is V2 to V6 (Vn, where "n" is the number of leaves with collars visible). Positional cloning and allelism and complementation tests revealed that a G-to-A mutation causing a Arg277-to-His277 substitution in ZmRNRL1, a ribonucleotide reductase (RNR) large subunit (RNRL), confers the tvt1-R mutant phenotype. RNR regulates the rate of deoxyribonucleoside triphosphate (dNTP) production for DNA replication and damage repair. By expression, yeast two-hybrid, RNA sequencing, and flow cytometric analyses, we found that ZmRNRL1-tvt1-R failed to interact with all three RNR small subunits at 34°C due to the Arg277-to-His277 substitution, which could impede RNR holoenzyme (α2ß2) formation, thereby decreasing the dNTP supply for DNA replication. Decreased dNTP supply may be especially severe for the SAM that requires a continuous, sufficient dNTP supply for rapid division, as demonstrated by the SAM arrest and tassel absence in tvt1-R mutants at restrictive temperatures. Our study reveals a novel mechanism of temperature-gated tassel formation in maize and provides insight into the role of RNRL in SAM maintenance.
Assuntos
Aclimatação/genética , Inflorescência/crescimento & desenvolvimento , Inflorescência/metabolismo , Ribonucleosídeo Difosfato Redutase/genética , Ribonucleosídeo Difosfato Redutase/metabolismo , Temperatura , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Variação Genética , Genótipo , Magnoliopsida/genética , Magnoliopsida/crescimento & desenvolvimento , Meristema/genética , Meristema/crescimento & desenvolvimento , Mutação , Mutação de Sentido Incorreto/fisiologiaRESUMO
The removal characteristics of antibiotic resistance genes and mobile genetic elements from livestock wastewater (dominated by quinolone antibiotics) treated with MFC were evaluated by High-throughput quantitative (HT-qPCR). The results showed that 144 ARGs and 8 MEGs were detected in the livestock wastewater. After MFC treatment, the number of AGRs decreased as a whole, and the relative abundance of macrolide-lincosamide-streptogramin group B (MLSB) and aminoglycosider decreased by 62.7% and 92.9%, respectively. MGEs decreased by 57.3% and multidrug genes decreased by 90%. After MFC treatment, the absolute abundance of tetracycline in raw sewage decreased by two orders of magnitude from 5.8 × 105 copies L-1 to 5.1.× 103 copies L-1. However, MFC was less efficient in the removal of vancomycin and beta-lactamase genes. It was also found that chloramphenicol resistance genes slightly increased. Illumina sequencing showed that Syntrophobacterales and Synergistales were predominant in MFCs. Desulfovibrio was resistant to high concentration of moxifloxacin hydrochloride. The removal efficiency of MFC for moxifloxacin hydrochloride at a concentration of 5 mg L-1 was 86.55%. The maximum power density and coulomb efficiency were 109.3 mV·cm-3 and 41.97%, respectively. With the increase of antibiotic concentration, the sewage treatment efficiency and electrical performance were inhibited. This study shows that untreated livestock wastewater had a great risk of gene horizontal transfer. Although MFC had limited treatment capacity for high-concentration quinolone wastewater, it is an effective method to reduce ARGs and the risk of horizontal gene transfer.
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Phenethyl glycosides having phenolic or methoxy functions at benzene rings are substances widely occurring in nature. This kind of compounds has been shown to have anti-oxidant, anti-inflammatory, and anticancer activities. However, some of them are not naturally abundant, thus the synthesis of such molecules is desirable. In this paper, natural phenethyl glycosides 3 and 4 were first totally synthesized from easily available materials with overall yields of 50.5% and 40.1%, respectively. And a new synthetic route to obtain natural phenethyl glycoside 2 in 46.2% yield was also described.
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Glicosídeos , Fenóis , Anti-Inflamatórios , Estrutura MolecularRESUMO
Anaerobic oxidation of methane (AOM) plays an important role in global carbon cycle and greenhouse gas emission reduction. In this study, an effective green technology to reduce methane emissions was proposed by introducing Mn-dependent anaerobic oxidation of methane (Mn-AOM) and microbial fuel cell (MFC) technology into constructed wetland (CW). The results indicate that the combination of biological methods and bioelectrochemical methods can more effectively control the methane emission from CW than the reported methods. The role of dissimilated metal reduction in methane control in CW and the biochemical process associated with Mn-AOM were also investigated. The results demonstrated that using Mn ore as the matrix and operating MFC effectively reduced methane emissions from CW, and higher COD removal rate was obtained in CW-MFC (Mn) during the 200 days of operation. Methane emission from CW-MFC (Mn) (53.76 mg/m2/h) was 55.61% lower than that of CW (121.12 mg/m2/h). The highest COD removal rate (99.85%) in CW-MFC (Mn) was obtained. As the dissimilative metal-reducing microorganisms, Geobacter (5.10%) was found enriched in CW-MFC (Mn). The results also showed that the presence of Mn ore was beneficial to the biodiversity of CW-MFCs and the growth of electrochemically active bacteria (EAB) including Proteobacteria (35.32%), Actinobacteria (2.38%) and Acidobacteria (2.06%), while the growth of hydrogenotrophic methanogens Methanobacterium was effectively inhibited. This study proposed an effective way to reduce methane from CW. It also provided reference for low carbon technology of wastewater treatment.
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Fontes de Energia Bioelétrica , Anaerobiose , Metano , Águas Residuárias , Áreas AlagadasRESUMO
Dyes and drugs with high toxicity and low biodegradability pose risk to human health and ecological security, and should be purified efficiently from effluents before discharge. Traditional adsorbents are limited by the insufficient active adsorption sites and low stability. In this study, a novel aminated magnetic adsorbent (MCTs) was fabricated via two cross-linking steps using chitosan and triethylenetetramine to fill the gaps between current adsorbent and performance requirements. The morphological and physicochemical characteristics of the as-prepared MCTs were determined and identified with the aid of several characterization techniques. The adsorption performance of dyes and drugs was also investigated and represented by their adsorption capacities. In particular, the adsorption capacities of Congo Red, Chicago Sky Blue, Reactive Brilliant Red, and Ibuprofen were 583.11, 465.01, 403.12, and 291.71 mg/g, respectively. They also remained at around 80% after four reuse cycles. MCTs were adsorbed via a monolayer spontaneous chemical reaction, and hydrogen bonding and electrostatic interaction were the dominant adsorption mechanisms. These results demonstrated that the preparation of MCTs via two cross-linking steps enhanced the adsorbents' adsorption capacity, reusability, and stability. They provided a new perspective for the preparation of high-efficient adsorbents and the purification of dye- and drug-polluted wastewater.
Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Adsorção , Chicago , Corantes , Humanos , Concentração de Íons de Hidrogênio , Cinética , Fenômenos MagnéticosRESUMO
Carbon dioxide (CO2) and methane (CH4) produced by denitrification bioreactors in processing agricultural surface runoff have contributed to increasing proportion of greenhouse gases (GHG) emissions. It is the first time to monitor and quantify the emission flux of CO2 and CH4 produced by laboratory-scale denitrification bioreactors which recycled waste Cunninghamia lanceolata sawdust (CLS) and industrial sludge (IS) as fillers to process simulated agricultural surface runoff. Sludge-water ratio, inflow rate and water flow direction are used as experimental factors to study the effect on the emission flux of CO2 and CH4. Results show that emission flux of CO2 from denitrification bioreactors with different sludge-water ratio approached 20 mg m-2h-1, simultaneously the average emission flux of CH4 produced by all bioreactors was 1.785 mg m-2h-1. The addition of sludge increased the emission flux of CH4 and had no significant effect on the emission flux of CO2. Increasing the inflow rate reduced the CO2 emission flux from 21.57 to 1.27 mg m-2h-1, and at the same time increased the CH4 emission flux from 0.007 to 9.54 mg m-2h-1. The gravity flow of wastewater reduced the emission flux of CO2 and CH4. The emissions of CO2 and CH4 from folded plate denitrification bioreactor with CLS and industrial sludge with a volume ratio of 1:2 can be reduced by 24.67% and 73.3%, respectively. There was no need to add special gas collection and treatment devices because CO2 and CH4 emission fluxes produced by the folded plate denitrification bioreactor and gravity denitrification bioreactor are not enough to increase the greenhouse effect. This study quantified the CO2 and CH4 produced by denitrification bioreactors filling CLS and IS, and provided a reference for future research on the gases produced by the denitrification process.