Association between CD24 Ala/Val polymorphism and multiple sclerosis risk: A meta analysis.

BACKGROUND: The aim of this study was to explore the association between CD24 Ala/Val polymorphism and susceptibility of multiple sclerosis (MS). METHODS: A comprehensive literature search for relevant studies was performed on google scholar, PubMed, Web of science, Embase, the Chinese National Knowledge Infrastructure and the Chinese Biology Medicine. This meta-analysis was conducted using the STATA 11.0 software and the pooled odds ratio with 95% confidence interval was calculated. RESULTS: Seven case-control studies were included in this meta-analysis. The results showed significant association between CD24 Ala/Val polymorphism and susceptibility to MS. Stratified analysis by areas also showed significant association in Asians. However, no association was found in Europeans. CONCLUSION: This study suggested that the CD24 Val allele was associated with an increased risk of MS and larger-scale studies of populations are needed to explore the role of CD24 Ala/Val polymorphism during the pathogenesis of MS.

[Nitrogen Removal Characteristics and Analysis of Microbial Community Structure in an IEM-UF Simultaneous Separation and Denitrification System].

A system that combines an ion exchange membrane and ultrafiltration membrane (IEM-UF) to form a simultaneous separation and denitrification system was proposed for domestic sewage with a low carbon/nitrogen ratio. The removal of nitrogen and COD in the system was studied under a three phase operating condition. The characteristics of the microbial community in each reactor were analyzed using metagenomics. The results show that, the average rate of ammonia nitrogen enrichment in the separator reached above 116.1% when the current intensity was 0.2 A. When the system was at C/N 2.80 and operating well, the average removal rates of COD and TN reached above 90% and 50%, respectively. The maximum removal rate of TN was above 65.4%. The results of metagenomics showed a genus of phylum Nitrospirae (Nitrospira) and a genus of phylum Proteobacteria (Nitrosomonas), with the proportions of 12.23% and 2.31%, respectively. In the denitrifying reactor, Dechloromonas, Thauera, and Azospira were detected in the proportions 4.57%, 1.76%, and 1.03%, respectively. These proportions were far larger than those of other bacteria in this reactor. Meanwhile, the presence of iron autotrophic denitrifying bacteria increased the denitrification efficiency of the system.

[Analysis of Low C/N Wastewater Treatment and Structure by the CEM-UF Combined Membrane-Nitrification/Denitrification System].

In this study, a CEM-UF composite membrane with ammonia nitrogen enrichment and separation characteristics was combined with nitrification/denitrification to treat low C/N wastewater. The denitrification characteristics of low C/N wastewater at different flow ratios were investigated, and the structural characteristics of functional microbial communities in nitrifying and denitrifying activated sludge were analyzed by 16Sr DNA high-throughput sequencing. The results showed that influent TN was 60 mg·L-1, COD/TN was 2.65, the nitrification effect of each flow rate was good, and the average ammonia nitrogen removal rate was 98.7%. When the flow ratio increased from 1:2 to 1:6, the m(COD)/m(NO3--N) of denitrification was increased, and the removal of average nitrate nitrogen reached its highest level at 1:6, which was 86.28%, and the removal of total nitrogen increased from 22.56% to 46.8%. An analysis of Illumina sequencing showed that nitrogen fixing bacteria Proteobacteria accounted for 30.9%, and the important nitrite oxidizing bacteria, Nitrospirae, accounted for 3.06%. At the genus level, Nitrosomonas and Nitrosospira, belonging to the ammonia oxidizing bacteria (AOB) category and Nitrospira and Nitrobacter, belonging to the nitrite oxidizing bacteria (NOB) category were detected. The ratio of AOB and NOB bacteria was high, which is consistent with good nitrification in the nitrification reactor. The dominant bacteria in denitrification sludge were Proteobacteria (53.13%), followed by Bacteroidetes (10.93%). A variety of bacteria related to denitrification were detected at the genus level, such as Dechloromonas, Thauera, Castellaniella, Alicycliphilus, Azospira, Comamonas, Caldilinea, and Saccharibacteria. The proportion of denitrifying bacteria was 25.91% as denitrifying bacteria microbial species were rich in the denitrifying sludge, giving a good denitrification effect.