Abstract
Background
N6-methyladenosine (m
6
A) RNA methylation and circular RNAs (circRNAs) have been shown to act vital roles in multiple malignancies including gastric cancer (GC). However, there ...is little knowledge about how m
6
A modification of circRNAs contributes to GC progression.
Methods
The association of METTL14 expression with the clinicopathological characteristics and prognosis in patients with GC was assessed by Western blot, Immunohistochemistry and public datasets. In vitro and vivo function experiments were conducted to investigate the role of METTL14 in GC. Furthermore, m
6
A-circRNA epitranscriptomic microarray was utilized to identify METTL14-mediated m
6
A modification of circRNAs, which were validated by methylated RNA immunoprecipitation (Me-RIP), RT-qPCR and rescue experiments in GC cells. The sponge of circORC5 with miR-30c-2-3p was confirmed by luciferase gene report and RNA immunoprecipitation assays. The expression, localization and prognosis of circORC5 in GC were evaluated by fluorescence in situ hybridization. The effects of METTL14 and (or) circORC5 on miR-30c-2-3p-mediated AKT1S1 and EIF4B were estimated by RT-qPCR and Western blot analyses.
Results
We found that METTL14 was downregulated in GC tissue samples and its low expression acted as a prognostic factor of poor survival in patients with GC. Ectopic expression of METTL14 markedly repressed growth and invasion of GC cells
in vitro
and
in vivo
, whereas knockdown of METTL14 harbored the opposite effects. Mechanically, m
6
A-circRNA epitranscriptomic microarray and Me-RIP identified circORC5 as the downstream target of METTL14. Silencing of METTL14 reduced the m
6
A level of circORC5, but increased circORC5 expression. Moreover, circORC5 could sponge miR-30c-2-3p, and reverse METTL14-caused upregulation of miR-30c-2-3p and downregulation of AKT1S1 and EIF4B. In addition, circORC5 possessed a negative correlation with miR-30c-2-3p and indicated a poor survival in GC.
Conclusion
Our findings demonstrate that METTL14-mediated m
6
A modification of circORC5 suppresses gastric cancer progression by regulating miR-30c-2-3p/AKT1S1 axis.
•A novel combined process for waste activated sludge dewatering was proposed.•Extracellular polymeric substances (EPS) were characterized by ultraviolet visible spectra.•Loosely, tightly bound EPS ...and bacterial cells in sludge flocs together affected the dewatering.•Tightly bound EPS provided some protective shielding allowing cells to survive.•The process disrupted EPS and cells, released the trapped water and promoted the dewatering.
The feasibility of electrolysis integrated with Fe(II)-activated persulfate (S2O82-) oxidation to improve waste activated sludge (WAS) dewaterability was evaluated. The physicochemical properties (sludge volume (SV), total suspended solids (TSS) and volatile suspended solids (VSS)) and extracellular polymeric substances (EPS), including slime EPS, loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were characterized to identify their exact roles in sludge dewatering. While dewaterability negatively corresponded to LB-EPS, TB-EPS, protein (PN) and polysaccharide (PS) in LB-EPS and TB-EPS, it was independent of SV, TSS, VSS, slime EPS and PN/PS. Further study through scanning electron microscope (SEM) verified the entrapment of bacterial cells by TB-EPS, protecting them against electrolysis disruption. Comparatively, electrolysis integrated with S2O82-/Fe(II) oxidation was able to effectively disrupt the protective barrier and crack the entrapped cells, releasing the water inside EPS and cells. Therefore, the destruction of both TB-EPS and cells is the fundamental reason for the enhanced dewaterability.
It is crucial to elucidate the release rate of microplastics (MPs) and phthalic acid esters (PAEs) in agricultural soil and their effects on crop productivity regarding film types and thicknesses. To ...address this issue, two-year landfill test was performed using 0.016 mm-thick polyethylene (PEt1) & biodegradable (BIOt1), and 0.01 mm-thin polyethylene (PEt2) & biodegradable (BIOt2) residual films as materials with no landfill as CK. Scanning electron microscopy (SEM) and infrared analyses revealed that two-year landfill caused considerable changes in physical forms and spectral peaks in BIO film, which was more pronounced in thin BIO (36.90 % weight loss). Yet, less changes were presented in the above analyzes in polyethylene (PE) films, and thick films damaged relatively less. MPs number was 86,829.11 n/kg in BIOt1 and 134,912.27 n/kg in BIOt2, equivalent to 2.55 and 3.72 times higher than in PEt1 and PEt2, respectively. This was closely associated with PAEs release, as soil PAEs concentration was substantially lower in PEt1 (17.60 g/kg) and PEt2 (21.43 g/kg) than in BIOt1 and BIOt2 (37.12 g/kg and 49.20 g/kg), respectively. Furthermore, maize productivity parameters were negatively correlated with the amount of MPs and PAEs. BIOt2 and PEt1 had the lowest and highest grain yield, respectively. BIO exhibited greater environmental risk and adverse effects on soil and crop productivity than PE film due to physical degradation and release of PAEs. Thickness-wise comparison exhibited that thin film residues had more adverse effect relative to thick film ones.
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•Thin BIO film showed numerous cracks, whereas no significant change on thick PE one.•The modification of spectral peaks was higher in BIO films but lower for thick PE.•BIO degraded quickly and released higher MPs and PAEs than PE residual films.•BIO residuals decreased soil BD, plant height, yield and WUE compared with PE ones.•Thin BIO and thick PE led to severe and slight environmental risks, respectively.
Intensive use of low-density polyethylene (LDPE) plastic films in agro-ecosystems has raised considerable concerns due to the increasing film residues in soils. It is unclear how the increased film ...residues affect soil properties and crop productivity and whether biodegradable (Bio) film can substitute LDPE. To address the issue, we designed a landfill experiment with different addition levels of plastic residue into soils of maize (Zea mays L.) field from 2018 to 2019. Six treatments were arranged as PMT1-T3/BioT1-T3, representing the low, medium, and high-level application of LDPE / Bio film fragments, with no residual film, applied as CK. Results show that, soil bulk density was significantly increased from 1.19 to 1.31 g/cm3 regardless of residue types. In contrast, soil porosity was lowered from 58.03% in CK to 57.36% in Bio and 56.12% in LDPE significantly (P < 0.05). Increased residues improved soil nitrogen level and lowered the C/N ratio significantly. Also, it decreased microbial biomass C and N levels but with no change in C/N (P < 0.05). Maize yield and WUE decreased, while soil water storage increased significantly. LDPE residues affected soil properties and productivity partly lower than Bio ones did, but the negative effects of them were similar in the maize field.
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•LDPE and Bio film residue significantly lowered maize productivity and water use.•Soil bulk density was thus increased while soil porosity decreased significantly.•Increased residues improved soil N content but lowered C/N ratio significantly.•Increased residues reduced microbial biomass C and N levels with no change in C/N.•Bio residues affected soil properties and productivity similarly as LDPE ones did.
Biodegradable (Bio) plastic films are widely viewed as promising alternative products of low-density polyethylene (LDPE) films to minimize plastic debris accumulation and pollution in agroecosystems. ...Yet, this speculation indeed lacks of sufficient evidences. We conducted a landfill investigation on the aging characteristics of Bio and LDPE plastic films in maize field, and the effects on soil aggregate composition and carbon & nitrogen stocks. The degradation rate of Bio film was up to 41.1% while that of LDPE film was zero. Scanning electron microscope (SEM) showed that the crack formation of Bio film had a pronounced domino effect, and FTIR showed that old Bio film displayed an extra wide peak threshold ranging from 3000 to 3500 cm−1. Particularly, the abundance of microplastics was elevated with the increased plastic residues, and the increment mostly resulted from Bio residues. Critically, plastic residues significantly lowered the soil macro-aggregates (>0.25 mm) proportion, while increasing that of micro-aggregates (0.1–0.25 mm) in LDPE, and silt/clay fraction (<0.1 mm) in Bio respectively. They significantly promoted total nitrogen content of the aggregates with the same size, but decreased the organic carbon content, dramatically lowering the C/N. Therefore, we first identified the fate of plastic film residues in agroecosystems and revealed the serious deficiencies of Bio plastic film.
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•Degradation rate of LDPE and Bio residue was 0% and 41% in maize field (two years).•Increased residues significantly lowered grain yield and WUE across two years.•Bio residues led to significantly higher microplastics abundance than LDPE ones.•Residues massively lowered the proportion of macro-aggregates and soil C/N ratio.•Bio film residues showed more serious risk on agroecosystems than LDPE ones did.
Environmental risk of multi-year polythene film mulching (PM) was evaluated and investigated. The location observation following 19-year (2000–2018) PM in irrigated region indicated that the ...cumulative accumulation of soil microplastics was as high as 2900 ± 19.5 n kg−1. Microplastic accumulation was tightly associated with soil plasticizer concentration (Pearson’s r = 0.728, p <0.05), and the concentration of dominant phthalic acid esters (PAEs) was up to 117.5–705 μg kg−1. As such, we conducted organic mulching substitute experiment (2019–2020) with non-mulching (CK), maize straw mulching (SM), living clover mulching (CM), PM, PM+SM and PM+CM respectively. The data showed that organic mulching (SM, CM) achieved similar productivity benefit as PM-involved treatments (p > 0.05). Critically, total concentration of PAEs decreased by 6.43% in SM relative to CK, and by 9.61% in PM+SM relative to PM respectively. High throughput sequencing indicated that the proportions of predominant bacteria and fungi were totally lower in PM than those of organic mulching, particularly Sphingomonadaceae and Stachybotryaceae. KEGG analyses indicated that organic mulching promoted the metabolisms of polycyclic aromatic hydrocarbons, benzoic acid (probability>75%) and heterologous organism metabolism (p<0.001), due to improved microbial community assembly. Therefore, organic mulching efficiently accelerated microbial mineralization of PM pollutants, and may act as a green solution to displace PM.
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•19-y polythene film mulching (PM) led to soil microplastics residue to 2900 n/kg.•Microplastic level was closely linked with soil phthalic acid esters (PAEs) level.•Crop straw or clover mulching evidently lowered PAEs concentration in soils.•Organic mulching significantly accelerated microbial mineralization of pollutants.•Organic mulching as a green solution achieved similar crop productivity as PM did.
A two-stage fermentation process combining hydrogen and methane production for the treatment of food waste was investigated in this paper. In hydrogen fermentation reactor, the indigenous mixed ...microbial cultures contained in food waste were used for hydrogen production. No foreign inoculum was used in the hydrogen fermentation stage, the traditional heat treatment of inoculum was not applied either in this bench scale experiment. The effects of the stepwise increased organic loading rate (OLR) and solid retention time (SRT) on integrated two-stage process were investigated. At steady state, the optimal OLR and SRT for the integrated two-stage process were found to be 22.65
kg
VS/m
3
d (160
h) for hydrogen fermentation reactor and 4.61 (26.67
d) for methane fermentation reactor, respectively. Under the optimum conditions, the maximum yields of hydrogen (0.065
m
3
H
2/kg
VS) and methane (0.546
m
3
CH
4/kg
VS) were achieved with the hydrogen and methane contents ranging from 29.42 to 30.86%, 64.33 to 71.48%, respectively. Biodegradability analysis showed that 5.78% of the influent COD was converted to the hydrogen in H
2-SCRD and 82.18% of the influent COD was converted to the methane in CH
4-SCSTR under the optimum conditions.
► Examined effects of plastic mulch on soil moisture-temperature and yield for potato. ► Mulching get higher and earlier emergence rates by raising soil temperature-moisture. ► Mulching prolonged the ...duration from seedling to maturity and increased dry matter. ► Short mulching duration increased tuber bulk and WUE. ► Removing mulch at 65 days after sowing got high yield and WUE for potato.
Effects of plastic mulching in ridges and furrows for varying durations on yield and water use efficiency (WUE) in potato were investigated in rainfed areas of north-western China in 2009 and 2010. The experiment comprised four mulched treatments (M50, M65, M80/85, and Mw – indicating plastic film mulch for 50, 65, and 80/85 d after sowing, and whole growth season, respectively – after which mulch in furrows was removed) and a non-mulched control. The results showed that film mulching warmed topsoil and increased topsoil water content. The daily mean topsoil temperature in mulched plots was 2.5–3.2
°C higher than that in controls during the early growing season (sowing–emergence), the difference became less as the plant canopy grew; on some days later in the season, the difference was even negative (i.e. the topsoil temperature in mulched was lower than in control plots). Seedlings under mulching emerged 8.1–11.7 d earlier than those in controls due to the increased topsoil temperature and moisture in the early season. Mulching also prolonged the duration from seedling to maturity by 0.7–15.0 d and significantly increased plant height, leaf area index, and dry matter. Compared to non-mulched plots, yields in mulched plots increased by 33.9–92.5% and 62.9–77.8% in 2009 and 2010, respectively, and corresponding WUEs improved by 41.4–112.6% and 45.9–70.6%. Both tuber yield and WUE were highest in M65. The data indicate that mulching for about 65 d after sowing was ideal to optimize soil moisture and soil temperature and in turn to improve potato productivity and WUE in this semi-arid rainfed region.
CYP152 peroxygenases catalyze decarboxylation and hydroxylation of fatty acids using H2O2 as cofactor. To understand the molecular basis for the chemo‐ and regioselectivity of these unique P450 ...enzymes, we analyze the activities of three CYP152 peroxygenases (OleTJE, P450SPα, P450BSβ) towards cis‐ and trans‐dodecenoic acids as substrate probes. The unexpected 6S‐hydroxylation of the trans‐isomer and 4R‐hydroxylation of the cis‐isomer by OleTJE, and molecular docking results suggest that the unprecedented selectivity is due to OleTJE’s preference of C2−C3 cis‐configuration. In addition to the common epoxide products, undecanal is the unexpected major product of P450SPα and P450BSβ regardless of the cis/trans‐configuration of substrates. The combined H218O2 tracing experiments, MD simulations, and QM/MM calculations unravel an unusual mechanism for Compound I‐mediated aldehyde formation in which the active site water derived from H2O2 activation is involved in the generation of a four‐membered ring lactone intermediate. These findings provide new insights into the unusual mechanisms of CYP152 peroxygenases.
The presence of a cis or trans Cα=Cβ double bond in unsaturated fatty acid substrates dramatically changes the catalytic efficiency and chemo‐/regioselectivity of three representative CYP152 peroxygenases including OleTJE, P450SPα, and P450BSβ, which provides new insights into their unusual catalytic mechanisms.
The two years field study assessed potato responses to various ridge-furrow plastic film mulching planting patterns in a rain-fed region. It showed that full mulching on the ridges and furrows (or ...the large and small ridges) increased both tuber yields and rain WUE, respectively, by over 70%. The full mulched ridges and furrows kept the topsoil warmer and wetter, decreased ET during the early growing season, thus enhanced the percentage of emergence and ensured faster development of seed tubers after planting. The full mulching extended the growth period from seedling to maturation, and enhanced plant height, LAI, R/S ratio and economic benefits of potato.
•Assessed potato responses to various ridge-furrow mulching planting patterns in a rain-fed region.•Full mulching increased both tuber yields and rain WUE, respectively, by over 70%.•Full mulching decreased evaporation during emergence and then increased ET.•Full mulching prolonged tuber bulking via increased early season topsoil temperature and moisture.
A planting pattern of alternate ridges and furrows with plastic film mulching has been viewed as a best management practice for crop production in the arid and semiarid regions, but there is a lack of insight into the underlying changes in soil–crop water relations on mulching areas and ridge-furrow shapes for potato (Solanum tuberosum L.) production. A field study with comparisons of three mulching areas and two ridge-furrow shapes was conducted for two years (2009 and 2010) to assess evapotranspiration, water use efficiency, and tuber yields in the semiarid Northwest China. The experiment included five mulching area and ridge-furrow shape combinations: (1) full mulching on double ridges and furrows (DRFFM), (2) full mulching on both ridges and furrows (RFFM), (3) half mulching only on ridges (RFHM), (4) no mulching on ridges and furrows (RFNM), and (5) traditional-flat planting and without mulching as the control (CK). The two full mulching treatments had the best effect on topsoil temperature–moisture, improved emergence rate by 9.3–14.4% and advanced emergence by 8.1–11.7 days (P<0.05). Full mulching treatments reduced evapotranspiration by about 24.0–45.0% during emergence, but increased it by up to 18.7% thereafter, primarily due to rapid increase of LAI under faster development, and also enhanced root/shoot ratio (P<0.05). Full mulching produced the highest tuber yields (57.4–78.2% higher than the CK) with higher cost of mulching material and labour than the half or no mulching treatments. The full mulching also resulted in the highest water use efficiency (increased by 56.8–70.3% than the CK). The beneficiary effects became smaller with the decrease of mulching areas. However, the difference between the two full mulching treatments was not significant (P>0.05) despite there was slightly higher WUE in DRFFM than RFFM. Our results revealed that the full mulching on ridge-furrow planting strategy was effective to increase potato productivity and water use efficiency in the semiarid area of Chinese Loess Plateau.
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