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The cross-linked poly(vinyl alcohol) (PVA)/poly(vinylidene fluoride) composite flat sheet membranes were successfully prepared by phase inversion method. Ferric trichloride (FeCl particles were used as cross-linker. PVA is cross-linked during the membrane fabrication. The structures of formed membranes were investigated using scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR). The hydrophilic contact angle, pure water flux, and tensile strength were measured to assess the membrane performance. The antifouling performance of modified membrane for the secondary effluent of urban sewage was evaluated by flux decline, washing recovery rate, fouling resistance analysis, and fractions distribution of different hydrophilicities. FTIR showed that the peak intensity, attributed to -OH groups, decrease gradually with the increase of FeCl3, indicating the formation of a PVA-Fe3+ net work structure. The addition of cross-linking agent FeCl3 confined the compaction of membranes, thus the fouling resistances of membranes were lower and the water flux was higher. When the weight ratio of PVA to FeCl3 was 1/0.09, the modified membranes had the best UF performance and antifouling property. [ABSTRACT FROM AUTHOR]

Owing to the symbiotic relationship between the microbiota and the human body, the microbiome is considered a "second human genome". Microorganisms are inextricably associated with human diseases and can affect the host phenotype. In the present study, 25 female patients with stage 5 chronic kidney disease (CKD5) undergoing hemodialysis in our hospital and 25 healthy subjects were recruited. The structure of the oral microbiota of the study participants was analyzed using the MiSeq PE300 sequencing platform and high-throughput 16S rDNA sequencing. The microbiota was compared between the groups using QIIME and the stats package in R. In total, 1,336 operational taxonomic units (OTUs) were obtained, and the relative frequencies of 450 OTUs differed significantly between the two groups (P < 0.05), indicating that the samples were rich in OTUs. A comparison of β-diversity indicated a significant difference in the microbial community structure between the two groups (P < 0.05). These results indicated that the biological diversity of the oral microbiota was highly correlated with CKD5. In this experiment, 189 genera, with significant differences in abundance between the groups (P < 0.05), were found. Furthermore, differences in the structure of the oral microbiota were observed between the groups at the phylum, class, order, family, and genus levels. Collectively, an imbalance in the oral microbiota may accelerate the progression of CKD and cause additional complications., Competing Interests: None., (AJTR Copyright © 2023.)

By adopting the bifunctional group reagent methylene-di-paraphenylene iso-cyanate (MDI), a ring antibiotic chiral stationary phase (CSP) was prepared in non-aqueous dimethylfomamide (DMF) with vancomycin which is a macrocyclic glycopeptide antibiotics bonded on gamma-amidopropyl silica gel. It was used in the chiral separation in high performance liquid chromatography. The results showed that vancomycin CSP synthesized in this way can be well used in enantiomer separation of the chiral compounds in normal and reversed-phase. It can be confirmed that the separation capability in reversed-phase is better than that in normal phase. Seventeen pairs of enantiomers were separated in reversed-phase mode, and the results showed a wide range of application. The phosphorus buffer system was better than the triethylamineacetic acid buffer system. The resolution of some chiral drugs such as D,L-dansyl amino acid has certain rule, and provides information about absolute configuration. The aging or denaturalization can not happen in the CSP when phase system was transformed, so it has some stability. The mechanism of the separation was analyzed and found to be the same as that of Armstrong.