Supplementing a specific synbiotic suppressed the incidence of AOM/DSS-induced colorectal cancer in mice.

In this study, we evaluated the effect of a specific synbiotic on CAC (AOM/DSS-induced colitis-associated cancer). We confirmed that the synbiotic intervention was able to protect the intestinal barrier and inhibit CAC occurrence via upregulating tight junction proteins and anti-inflammatory cytokines, and downregulating pro-inflammatory cytokines. Moreover, the synbiotic significantly improved the disorder of the colonic microbiota of CAC mice, promoted the formation of SCFAs and the production of secondary bile acids, and alleviated the accumulation of primary bile acids in the CAC mice. Meanwhile, the synbiotic could significantly inhibit the abnormal activation of the intestinal Wnt/ß-catenin signaling pathway significantly related to IL-23. In a word, the synbiotic can inhibit the occurrence and development of colorectal tumors and it may be a functional food to prevent inflammation-related colon tumors, and the research also provided a theoretical basis for improving the intestinal microecological environment through diet therapy.

Analysis of drug resistance genes of integrons in clinical isolates of Escherichia coli from elderly bloodstream infections.

This experiment was carried out to provide a basis for the treatment of clinical bloodstream infections by analyzing the drug resistance characteristics and integrated gene distribution of Escherichia coli in bloodstream infections in elderly patients. For this aim, E. coli were collected for bacterial identification and drug sensitivity testing from bloodstream infections in elderly patients in the hospital from January 2016 to December 2019. ESBLs positive strains were assayed for genotypes and their integron carriage rates by PCR amplification. The characteristics and differences of various genotype rates were compared and analyzed. Results showed that a total of 230 E. coli strains were isolated. The detection rate of ESBLs-producing bacteria was 37.39 %. ESBLs-producing E. coli showed a high rate of resistance to cefepime, levofloxacin, cotrimoxazole, and ticarcillin/clavulanic acid (>40%). The resistance rate of 230 strains of E. coli to meropenem, minocycline, amikacin, gentamicin and cefoxitin was less than 20%. Among the ESBLs-producing E. coli in bloodstream infections in elderly patients, CTX-M-9 accounted for 27.91%, CTX-M-2 for 17.44%, and SHV for 13.95%. The detection rate of type I integrated genes was 41.30%, and type II and III integrated genes were not detected. ESBLs-producing genotyping-positive bacteria were detected with more than 50% of type I integrated genes. It was concluded that type I integrated genes in ESBLs-producing E. coli isolated from elderly patients carried resistance genes such as CTX-M-9 and CTX-M-2 aggravating multi-drug resistance in bacteria.

Dilational Rheological Properties of Surfactants at the Crude Oil-Water Interface: The Effect of Branch-Preformed Particle Gels and Polymers.

The interfacial properties of a heterogeneous composite flooding system containing a surfactant fatty alcohol polyoxyethylene carboxylate (C12EO3C), branched-preformed particle gel (B-PPG), and polymer partly hydrolyzed polyacrylamide (HPAM) at the crude oil-water interface were investigated by a dilational rheology method. The results demonstrated that the C12EO3C molecules can form an elastic interfacial film with certain strength at the crude oil-water interface. The addition of HPAM to the C12EO3C solution has a detrimental effect on the interfacial film formed by C12EO3C molecules, leading to a decrease in the dilational modulus and an increase in the phase angle. Moreover, the addition of B-PPG to the C12EO3C solution also disrupts the stability and strength of the interfacial film of C12EO3C. In particular, linear HPAM with a lower steric hindrance is more likely to insert into the interfacial film of C12EO3C; thus, HPAM possesses a stronger destruction ability for the interfacial film of C12EO3C than B-PPG. When HPAM is compounded with B-PPG, a superimposed effect exists to cause more severe disruption for the interfacial film. The heterogeneous composite flooding system not only enhances oil recovery by increasing the viscosity of the bulk phase but also weakens the interfacial film to facilitate the post-treatment of the recovered crude oil. Thus, the heterogeneous composite flooding system exhibits promising prospects in practical application.

Influence of the Injection Scheme on the Enhanced Oil Recovery Ability of Heterogeneous Phase Combination Flooding in Mature Waterflooded Reservoirs.

With the maturity of waterflooded reservoirs, owing to serious heterogeneity, the fluid will channel through the thief zone, leading to considerable remaining oil unrecovered in the upswept area. To further enhance oil recovery (EOR) after waterflooding, the heterogeneous phase combination flooding (HPCF) was composed of a polymer, branched-preformed particle gel (B-PPG), and surfactant. For the sake of improving the economic efficiency, the influence of the injection scheme on the EOR of HPCF with an equal chemical agent cost was investigated by sand-pack flooding experiments. Then, visual plate sand-pack model flooding experiments were performed to study the swept area of HPCF under different injection schemes. Results demonstrated that the total EOR of HPCF under different injection schemes ranged from 33.5 to 39.3%. Moreover, the EOR of HPCF under the alternation injection (AI) scheme was the highest, followed by the concentration step change injection (CI) scheme, and that of the simultaneous injection (SI) scheme was the least. The visual flooding experimental results showed that the swept area of HPCF after waterflooding under the AI scheme was higher than that of the SI. Moreover, in view of qualitative analysis of remaining oil distribution, the EOR of AI of HPCF was higher than that of SI, which was consistent with the parallel sand-pack flooding results.