The corrosion behavior of carbon steel under coexistence of carbon dioxide and SRB.

The corrosion behavior of carbon steel under the coexistence of carbon dioxide and SRB was studied by means of corrosion weight loss, SEM, EDS, in situ pH test, and other methods. The results showed that Chloride ions, temperature, pH, and oxygen coexist with iron bacteria will affect the corrosion under the coexistence of CO2 and SRB, and SRB tends to grow in a favorable environment for itself, and the corrosion rate of X52N at 42 days is slightly higher than that at 21 days. However, the pitting depth increased sharply from 21.20 µm in 21 days to 39.79 µm in 42 days. So that the corrosion can be divided into two stages. First, SRB catalyze the dissolution of FeCO3, leading to local uniform corrosion. Second, SRB directly obtain electrons from the metal surface, resulting in local pitting. In addition, the environment under the stable mineralized biofilm was found to be slightly alkaline.

Glycine-Ti3C2Tx Hybrid Material Improves the Electrochemical Corrosion Resistance of a Water-Borne Epoxy Coating.

Improving the dispersibility and compatibility of nanomaterials in water-borne epoxy resins is an important means to improve the protection ability and corrosion resistance of coatings. In this study, glycine-functionalized Ti3C2Tx (GT) was used to prepare an epoxy composite coating. The results of Fourier transform infrared spectroscopy and X-ray diffraction showed that glycine was successfully modified. The scanning electron microscopy and transmission electron microscopy results showed that the aggregation of Ti3C2Tx was alleviated. Electrochemical impedance spectroscopy test results show that, after 60 days of immersion, GT coating still shows the best protection performance, and the composite coating |Z|f = 0.01 Hz is 3 orders of magnitude higher than that of the pure epoxy coating. This is mainly because, after adding glycine, the -COOH group on the surface of glycine binds to the -OH group on the surface of Ti3C2Tx, improving the aggregation of Ti3C2Tx itself. At the same time, the -NH group of glycine can also participate in the curing reaction of epoxy resin to strengthen the bonding strength between the coating and the metal. The good dispersion of GT in epoxy resin makes it fill the pores and holes left by epoxy resin curing and strengthen the corrosion resistance. The easy availability and green properties of glycine provide a simple and environmentally friendly method for the modification of Ti3C2Tx.

A collaborative effect of solid-phase denitrification and algae on secondary effluent purification.

This study explored the collaborative effect on nutrients removal performance and microbial community in solid-phase denitrification based bacteria-algae symbiosis system. Three biodegradable carriers (apple wood, poplar wood and corncob) and two algae species (Chlorella vulgaris and Chlorella pyrenoidosa) were selected in these bacteria-algae symbiosis systems. Results demonstrated that corncob as the carrier exhibited the highest average removal efficiencies of total nitrogen (83.7%-85.1%) and phosphorus removal (38.1%-49.1%) in comparison with apple wood (65.8%-71.5%, 25.5%-32.7%) and poplar wood (42.5%-49.1%, 14.2%-20.7%), which was mainly attributed to the highest organics availability of corncob. The addition of Chlorella acquired approximately 3%-5% of promotion rates for nitrated removal among three biodegradable carriers, but only corncob reactor acquired significant promotions by 3%-11% for phosphorous removal. Metagenomics sequencing analysis further indicated that Proteobacteria was the largest phylum in all wood reactors (77.1%-93.3%) and corncob reactor without Chlorella (85.8%), while Chlorobi became the most dominant phylum instead of Proteobacteria (20.5%-41.3%) in the corncob with addition of Chlorella vulgaris (54.5%) and Chlorella pyrenoidosa (76.3%). Thus, the higher organics availability stimulated the growth of algae, and promoted the performance of bacteria-algae symbiosis system based biodegradable carriers.

Simultaneous denitrification and organics removal by denitrifying bacteria inoculum in a multistage biofilm process for treating desulfuration and denitration wastewater.

This study aimed to treat real wastewater from the desulfuration and denitration process in a petrochemical plant with high-strength nitrogen (TN≈200 mg/L, > 90% nitrate), sulfate (2.7%) and extremely low-strength organics (CODCr < 30 mg/L). Heterotrophic denitrification of multistage anoxic and oxic biofilm (MAOB) process in three tanks using facultative denitrifying bacteria inoculum was developed to simultaneously achieve desirable effluent nitrogen and organics at different hydraulic retention time (HRT) and carbon to nitrogen (C/N) mass ratios. The optimum condition was recommended as a C/N ratio of 1.5 and a HRT of A (24 h)/O (12-24 h) to achieve > 90% of nitrogen and organics removal as well as no significant variation of sulfate. The denitrifying biofilm in various tanks was dominant by Hyphomicrobium (8.9%-25.7%), Methylophaga (18.6%-25.8%) and Azoarcus (3.3%-19.6%), etc., containing > 20% aerobic denitrifiers. This explained that oxic zone in MAOB process also exhibited simultaneous nitrogen and organics removal.

Improving denitrification performance of biofilm technology with salt-tolerant denitrifying bacteria agent for treating high-strength nitrate and sulfate wastewater from lab-scale to pilot-scale.

This study focused on the application of salt-tolerant denitrifying bacteria (DBA) in an optimized biofilm process to treat high sulfate-nitrate wastewater from lab-scale to pilot-scale. Lab-scale results demonstrated the salinity, DBA inoculum, supplementary carbon and phosphorus source significantly varied the startup periods at the range of 36-74 d, and the optimum initial start-up conditions were as follows: >0.6 g/L of DBA, 2-4 of C/N ratio, 0.3-0.6 mg/L of phosphorus and a salinity-gradient domestication method. A pilot scale of biofilm technology with DBA was further developed for treating real wastewater from the desulfuration and denitration with both high nitrate (≈200 mg/L) and sulfate (2.7%). The denitrification efficiency reached above 90% after one-month gradient-salinity of 0.5%-2.7%. Mature biofilm had dominant genera Hyphomicrobium (31.80%-61.35%), Methylotenera (0.85%-20.21%) and Thauera (1.42%-8.40%), etc. Notably, the largest genera Hyphomicrobium covered the complete denitrification genes.

Microbial communities and sediment nitrogen cycle in a coastal eutrophic lake with salinity and nutrients shifted by seawater intrusion.

Coastal waters are often influenced by seawater intrusion and terrestrial emissions because of its special location. In this study, the dynamics of microbial community with the role of nitrogen cycle in sediment in a coastal eutrophic lake were studied under a warm season. The water salinity gradually increased from 0.9‰ in June to 4.2‰ in July and 10.5‰ in August because of seawater invasion. Bacterial diversity of surface water was positively related with salinity and nutrients of total nitrogen (TN) as well as total phosphorus (TP), but eukaryotic diversity had no relationship with salinity. In surface water, algae belonging to Cyanobacteria and Chlorophyta were dominant phyla in June with the relative abundances of >60%, but Proteobacteria became the largest bacterial phylum in August. The variation of these predominant microbes had strong relationship with salinity and TN. In sediment, the bacterial and eukaryotic diversity was greater than that of water, and a significantly different microbial community was observed with dominant bacterial phyla Proteobacteria and Chloroflexi, and dominant eukaryotic phyla Bacillariophyta, Arthropoda, and Chlorophyta. Proteobacteria was the only enhanced phylum in the sediment with the highest relative abundance of 54.62% ± 8.34% due to seawater invasion. Denitrifying genera (29.60%-41.81%) were dominant in surface sediment, then followed by microbes related to nitrogen fixation (24.09%-28.87%), assimilatory nitrogen reduction (13.54%-19.17%), dissimilatory nitrite reduction to ammonium (DNRA, 6.49%-10.51%) and ammonification (3.07%-3.71%). Higher salinity caused by seawater invasion enhanced the accumulation of genes involved in dentrificaiton, DNRA and ammonification, but decreased genes related to nitrogen fixation and assimilatory nitrogen reduction. Significant variation of dominant genes of narG, nirS, nrfA, ureC, nifA and nirB mainly caused by the changes in Proteobacteria and Chloroflexi. The discovery of this study would be helpful to understand the variation of microbial community and nitrogen cycle in coastal lake under seawater intrusion.

Enhanced fatty acid oxidation mediated by CPT1C promotes gastric cancer progression.

BACKGROUND: Carnitine palmitoyltransferase 1C (CPT1C) is a critical enzyme that catalyzes carnitinylation of fatty acids for transport into mitochondria for ß-oxidation. No previous studies have been conducted to explore the prognostic and oncogenic role of CPT1C in gastric cancer (GC). METHODS: Public RNA-sequencing data and micro-array data were extracted from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases respectively. Survival analysis was performed in TCGA and GSE62254 cohorts. RT-qPCR and Western blot analyses were used to determine genes expression in GC cells. Fatty acid oxidation (FAO) assay kit was used to examine cell FAO rate. The cell proliferation ability and cell cycle were tested by using CCK-8 and cell cycle assay kits. RESULTS: In the both TCGA and GSE62254 cohorts, high expression of CPT1C was significantly associated with poor overall (OS) (P<0.001) and disease free survival (DFS) of GC patients (P<0.001). Silence of CPT1C significantly inhibited cell FAO rate, suppressed cell proliferation and induced cell cycle arrest, while enforced CPT1C expression had the opposite effects. However, etomoxir treatment completely restricted the increase of FAO rate, cell viability and the phase of DNA synthesis caused by enhanced CPT1C expression. Of note, CPT1C expression was transcriptionally activated by hypoxia inducible factor-1α. CONCLUSIONS: High expression of CPT1C induced by hypoxia was closely associated with poor prognosis and can promote proliferation of GC cells.

Complete genome sequence of an IMP-8, CTX-M-14, CTX-M-3 and QnrS1 co-producing Enterobacter asburiae isolate from a patient with wound infection.

OBJECTIVES: The aim of this study was to investigate the characteristics and complete genome sequence of an IMP-8, CTX-M-14, CTX-M-3 and QnrS1 co-producing multidrug-resistant Enterobacter asburiae isolate (EN3600) from a patient with wound infection. METHODS: Species identification was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Carbapenemase genes were identified by PCR and Sanger sequencing. The complete genome sequence of E. asburiae EN3600 was obtained using a PacBio RS II platform. Genome annotation was done by Rapid Annotation using Subsystem Technology (RAST) server. Acquired antimicrobial resistance genes (ARGs) and plasmid replicons were detected using ResFinder 2.1 and PlasmidFinder 1.3, respectively. RESULTS: The genome of E. asburiae EN3600 consists of a 4.8-Mbp chromosome and five plasmids. The annotated genome contains various ARGs conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones, fosfomycin, macrolides, phenicols, rifampicin and sulfonamides. In addition, plasmids of incompatibility (Inc) groups IncHI2A, IncFIB(pECLA), IncFIB(pQil) and IncP1 were identified. The genes blaIMP-8, blaCTX-M-14 and blaCTX-M-3 were located on different plasmids. The blaIMP-8 gene was carried by an 86-kb IncFIB(pQil) plasmid. The blaCTX-M-3 and qnrS1 genes were co-harboured by an IncP1 plasmid. In addition, blaCTX-M-14 was associated with blaTEM-1B, blaOXA-1, catB3 and sul1 genes in a 116-kb non-typeable plasmid. CONCLUSION: To our knowledge, this is the first complete genome sequence of an E. asburiae isolate co-producing IMP-8, CTX-M-14, CTX-M-3 and QnrS1. This genome may facilitate the understanding of the resistome, pathogenesis and genomic features of Enterobacter cloacae complex (ECC) and will provide valuable information for accurate identification of ECC.

High expression of MMP19 is associated with poor prognosis in patients with colorectal cancer.

BACKGROUND: Matrix metalloproteinase 19 (MMP19) is a member of zinc-dependent endopeptidases, which have been involved in various physiological and pathological processes. Its expression has been demonstrated in some types of cancers, but the clinical significance of MMP19 in colorectal cancer (CRC) has not been reported. Thus, we aimed to analyze the clinical significance of MMP19 in CRC in present study. METHODS: The expression of MMP19 was first explored in The Cancer Genome Atlas (TCGA) cohort, and then validated in the GSE39582 cohort and our own database. Clinicopathological features and survival rate were also investigated. RESULTS: MMP19 was found to be a predictor for overall survival (OS) in both univariate (hazard ratio [HR]: 1.449, 95% confidence interval [CI]: 1.108-1.893, P = 0.007) and multivariate survival analyses (HR: 1.401, 95% CI: 1.036-1.894, P = 0.028) in the TCGA database. MMP19 was further validated as an independent factor for recurrence free survival in the GSE39582 database by both univariate analysis (HR: 2.061, 95%CI: 1.454-2.921, P < 0.001) and multivariate analysis (HR = 1.470, 95% CI: 1.025-2.215, P = 0.032). In an in-house cohort, MMP19 was significantly upregulated in CRC tissues when compared with their adjacent normal controls (P < 0.001). Ectopic MMP19 expression was positively associated with lymph node metastases (P = 0.029), intramural vascular invasion (P = 0.015) and serum carcinoembryonic antigen levels (P = 0.045). High MMP19 expression correlated with a shorter OS (HR = 5.595; 95% CI: 2.573-12.164; P < 0.001) and disease free survival (HR = 4.699; 95% CI: 2.461-8.974; P < 0.001) in multivariate cox regression analysis. CONCLUSIONS: Expression of MMP19 was upregulated in CRC. High expression of MMP19 was determined to be an independent and poor prognostic factor in CRC. These results suggest that MMP19 may be a good biomarker for CRC.

Screening key lncRNAs for human rectal adenocarcinoma based on lncRNA-mRNA functional synergistic network.

BACKGROUND: Rectal adenocarcinoma (READ) is one of the deadliest malignancies, and the molecular mechanisms underlying the initiation and development of READ remain largely unknown. In this study, we aimed to find key long noncoding RNAs (lncRNAs) and mRNAs in READ by RNA sequencing. METHODS: RNA sequencing was performed to identify differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) between READ and normal tissue. READ-specific protein-protein interaction (PPI), DElncRNA-DEmRNA coexpression, and DElncRNA-nearby DEmRNA interaction networks were constructed. DEmRNAs and DEmRNAs coexpressed with DElncRNAs were functionally annotated. RESULTS: A total of 2113 DEmRNAs and 150 DElncRNAs between READ and normal tissue were identified. The PPI network identified several hub proteins, including CDK1, AURKB, CDC6, FOXQ1, NUF2, and TOP2A. The DElncRNA-DEmRNA coexpression and DElncRNA-nearby DEmRNA interaction networks identified some hub lncRNAs, including CCAT1, LOC105374879, GAS5, and B3GALT5-AS1. The colorectal cancer pathway, the intestinal immune network for IgA production and the p53 signaling pathway were three pathways significantly enriched in DEmRNAs and DEmRNAs coexpressed with DElncRNAs. MSH6 coexpressed with two DElncRNAs (LOC105374879 and CASC15) and BCL2 coexpressed with B3GALT5-AS1 were significantly enriched in the colorectal cancer signaling pathway. TNFRSF17 coexpressed with B3GALT5-AS1 was enriched in the intestinal immune network for IgA production. CCNB2 coexpressed with LOC105374879 was enriched in the p53 signaling pathway. CONCLUSION: A total of four DEmRNAs (MSH6, BCL2, TNFRSF17, and CCNB2) and three DElncRNAs (LOC105374879, CASC15, and B3GALT5-AS1) may be involved in the pathogenesis of READ; this data may contribute to understanding the mechanisms of READ and the development of therapeutic strategies for READ.

The KLF14 Transcription Factor Regulates Glycolysis by Downregulating LDHB in Colorectal Cancer.

The Krüppel-like transcription factor 14 (KLF14) is a critical regulator of a wide array of biological processes. However, the role of KLF14 in colorectal cancer (CRC) isn't fully investigated. This study aimed to explore the clinicopathological significance and potential role of KLF14 in the carcinogenesis and progression of CRC. A tissue microarray consisting of 185 samples from stage I-III CRC patients was adopted to analyze the correlation between KLF14 expression and clinicopathological parameters, as well as overall survival (OS) and disease-free survival (DFS). The underlying mechanisms of altered KLF14 expression on glycolysis were studied using in vitro and patients' samples. The results showed that KLF14 expression was downregulated in CRC than their normal controls. Low KLF14 expression correlated with advanced T stage (P< 0.001) and N stage (P= 0.040), and larger tumor size (P= 0.008). Lost KLF14 expression implied shorter OS and DFS after colectomy in both univariate and multivariate survival analysis (P<0.05). Experimentally, restore KLF14 expression significantly decreased the rate of glycolysis both in vitro and in patients' sample. Mechanically, KLF14 regulated glycolysis by downregulating glycolytic enzyme LDHB. Collectively, KLF14 is a novel prognostic biomarker for survival in CRC, and downregulation of KLF14 in CRC prompts glycolysis by target LDHB. Hence, KLF14 could constitute potential prognostic predictors and therapeutic targets for CRC.

Lidocaine inhibits proliferation and induces apoptosis in colorectal cancer cells by upregulating mir-520a-3p and targeting EGFR.

Lidocaine is a conventional local anesthetic which is shown antiproliferative of colorectal cancer (CRC) in patients. MicroRNAs (miRNAs) have been consistently demonstrated to be involved in CRC, and miR-520a-3p could suppress CRC migration, promote apoptosis by targeting epidermal growth factor receptor (EGFR). However, the mechanism by which lidocaine regulated CRC proliferation and apoptosis remains unknown. In this study, quantitative RT-PCR were used to measure miR-520a-3p and EGFR expression levels, and western blotting assays ware performed to measure EGFR expression in CRC cells. Luciferase reporter assay was employed to validate the direct targeting of EGFR by miR-520a-3p. Cell proliferation and apoptosis assays ware utilized to analyze the role of lidocaine in CRC cells. The results indicated that 500 and 1000 µM lidocaine over 24 h inhibited proliferation and induced apoptosis of CRC cells. Compared with the control group, the expression of EGFR was suppressed by lidocaine (500 µM) in CRC cells. Furthermore, miR-520a-3p could directly targets EGFR in CRC cells. Lidocaine (500 µM) increased the expression of miR-520a-3p and rescued the reduction of miR-520a-3p caused by miR-520a-3p inhibitor. The results suggested that lidocaine could suppress the expression of EGFR by upregulating miR-520a-3p, and it could induce apoptosis and inhibit proliferation in CRC cells. Lidocaine may serve as potential therapeutic regimen for colorectal cancer.

NOTCH4 Is a Novel Prognostic Marker that Correlates with Colorectal Cancer Progression and Prognosis.

Notch family plays vital role in carcinogenesis and progression of various cancer, however, its clinical significance and prognostic value in colorectal cancer isn't fully investigated. In present study, we first investigated the NOTCH4 expression in The Cancer Genome Atlas (TCGA) (n=361) and GSE39582 (n=474) database and then validated with our own database (n=248). The transcriptional and protein levels of NOTCH4 were evaluated by RT-PCR and immunohistochemistry study, respectively. Univariate and multivariate survival analyses were performed to explore the relationship between various prognostic factors and survival outcomes. In the univariate analysis, NOTCH3 and NOTCH4 were significantly correlated with prognosis in TCGA and GSE39582 database, respectively (P<0.05). For NOTCH3 has been studied in CRC, we chosen NOTCH4 for further study. NOTCH4 mRNA was higher in liver metastases than their primary colorectal cancer or normal mucosa. Increased NOTCH4 levels significantly correlated with advanced N stage (P= 0.002), M stage (P= 0.002), lymphovascular invasion (P= 0.026), and CEA status (P= 0.030). Patients with high NOTCH4 expression had shorter 5-year disease-free survival (DFS) (HR 6.809; 95% CI 3.334-13.904; P< 0.001) and overall survival (OS) (HR 6.476; 95% CI 3.307-12.689; P<0.001) than those with low NOTCH4 expression. Multivariate survival analysis demonstrated that NOTCH4 was an independent prognostic biomarker for both DFS (HR 7.848; 95% CI 3.777-16.308; P<0.001) and OS (HR 5.323; 95% CI 2.668-10.623; P<0.001).Collectively, NOTCH4 may play critical role in colorectal cancer progression and could serve as a novel biomarker to predict survival after colectomy.