Microbiological Advances in Orthodontics: An Overview and Detailed Analysis of Temporary Anchorage Devices.

Dental biofilm is the initiating factor of oral diseases, such as periodontitis and caries. Orthodontic treatment could alter the microbiome structure balance, and increase the risk of such diseases. Furthermore, fixed appliances can induce temporary changes in the microbiome community, and the changes that clear aligners bring are smaller by comparison. Temporary anchorage devices (TADs) are skeletal anchorages that are widely used in orthodontic treatment. Microorganisms affect the occurrence and development of inflammation surrounding TADs. At present, existing researches have verified the existence of plaque biofilm on the surface of TADs, but the formation of plaque biofilm and plaque composition under different stable conditions have not been fully understood. The development of high-throughput sequencing, molecular biology experiments, and metabonomics have provided new research ideas to solve this problem. They can become an effective means to explore the microbiome surrounding TADs.

m6A transferase METTL3 regulates endothelial-mesenchymal transition in diabetic retinopathy via lncRNA SNHG7/KHSRP/MKL1 axis.

Diabetic retinopathy is one of the microvascular complications in diabetic patients and the leading cause of blindness worldwide. The levels of METTL3, lncRNA SNHG7, KHSRP, MKL1, endothelial and mesenchymal markers were determined by RT-qPCR or western blot assays in vitro and in vivo. H&E staining was used to observe the retinal structure in a mouse model of DR. The expression levels of METTL3 and SNHG7 were significantly downregulated in DR patients, DR mice and high glucose-induced HRMECs cells. Notably, METTL3 installed the m6A modification and enhanced the stability of SNHG7. Besides, METTL3 inhibited HRMECs EndoMT by promoting the expression of SNHG7. Additionally, SNHG7 was found to weaken MKL1 mRNA stability by binding to the RNA-binding protein KHSRP. Furthermore, we verified that METTL3 regulated EndoMT in DR through the SNHG7/MKL1 axis. We conclude that METTL3 regulates endothelial-mesenchymal transition in DR via the SNHG7/KHSRP/MKL1 axis, providing a new target for DR treatment.

MSC-derived exosomal lncRNA SNHG7 suppresses endothelial-mesenchymal transition and tube formation in diabetic retinopathy via miR-34a-5p/XBP1 axis.

AIMS: Diabetic retinopathy (DR) is the most common complication of type 2 diabetes mellitus, which could result in visual impairment. Accumulating studies have shown the implication of long non-coding RNAs (lncRNAs) in the pathogenesis of DR. Our aims are to investigate whether lncRNA SNHG7 plays a role during DR pathogenesis. MAIN METHODS: Human retinal microvascular endothelial cells (HRMECs) were treated with high glucose (HG) to build cell model. Relative expression of RNAs were examined using qPCR, and western blot or immunofluorescence analysis was adopted to detect the protein expression. Cell viability, migration and angiogenic capacity of HRMECs were estimated through CCK-8, transwell and tube formation experiments, respectively. Dual-luciferase reporter and RNA pull down assays were employed to verify the interplay between miR-34a-5p and SNHG7 or XBP1. Mesenchymal stem cells (MSCs) were identified by examining typical surface makers using flow cytometry and the differentiation abilities via Alizarin red, Oil red O and Alcian blue staining. MSC-derived exosomes were verified by transmission electron microscopy and western blot. KEY FINDINGS: LncRNA SNHG7 sponged to and negatively regulated miR-34a-5p. SNHG7 overexpression repressed HG induced endothelial-mesenchymal transition (EndMT) and tube formation of HRMECs, while miR-34a-5p overexpression could reverse this effect. miR-34a-5p targeted and negative regulated XBP1. Knockdown of miR-34a-5p repressed HG induced EndMT and tube formation, which were partially blocked by XBP1 inhibition. MSC-derived exosomes could transfer SNHG7 to HRMECs and modulated EndMT and tube formation. SIGNIFICANCE: The MSC-derived exosomal lncRNA SNHG7 suppresses EndMT and tube formation in HRMECs via miR-34a-5p/XBP1 axis.

[Assessment of Emission and Co-Reduction of PCDD/Fs and PCNs in the Secondary Copper Production Sector].

Polychlorinated naphthalenes (PCNs) could he generated and discharged unintentionally in the secondary copper production industry with similar mechanisms as PCDD/Fs during high-temperature industrial processes. Therefore, measures that reduce the release of PCDD/Fs will also reduce PCNs emissions. Analysis of the technical process and correlation with their emissions will provide theoretical basis for co-mitigation of PCNs and PCDD/Fs. The production process of secondary copper was analyzed, with key production stages of discharge identified through monitoring the emissions of two kinds of pollutants. Co-reduction technologies were screened and specified. Three recommendations on co-mitigation of the two pollutants were provided to support the implementation of Stockholm Convention and UPOPs reduction in the secondary copper production sector in China. Key words:secondary copper industry; smelting; PCNs; PCDD/Fs; co-mitigation

[Analysis of characteristics of dioxin contamination in the chlor-alkali site that uses graphite anode for production].

In order to find out the characteristics of dioxin contamination, we sampled and analyzed the soil and groundwater on a chlor-alkali factory site that uses graphite anode for production. The results show that the toxic equivalent quantity (TEQ) of dioxins in soil samples exceeds the U. S. EPA region screening value (RSL), with the chlorine hydrogen processing workshop, the electric tank workshop, the asbestos stack area, the sewage treatment plant and the oil depot were affected. The dioxin concentration limit of the groundwater sample doesn't exceed the drinking water standard of China. Considering the fingerprints characteristics of dioxin-contaminated concentration, dioxin isomers content and TEQ, the priority pollutants for control on this site are 2,3,7,8-TCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, OCDD and 2,3,7,8-TCDD. The results show that dioxin pollution is very serious in the chlor-alkali plant that uses graphite anode for production, and the environmental supervision is imperative.

[Formation mechanism of by-product PCBs in the p-DCB production].

A typical p-DCB production process was selected in this study. A series of p-DCB product samples, 1 Japanese sample and 1 chlorobenzene sample were collected and analyzed for by-product polychlorinated biphenyls (PCBs). It is a common phenomenon that byproduct PCBs exists in the p-DCB production process. The PCBs levels in the p-DCB samples were 62-781 ng/g and the highest WHO-TEQ in the process was 0.24 ng/g, while the PCBs level in the Japanese sample reached 881 ng/g. PCB31 was the dominate PCB congener in all the p-DCB samples with the maximum 98.5% of the total PCBs. Maximum content of PCBs was TrCBs in the p-DCB samples with the next TeCBs, DiCBs and PeCBs, while MoCBs were the highest in the chlorobenzene sample. Furthermore, a formation mechanism of PCBs in the production process was proposed and proved by the analysis result. It suggested that the formation of PCBs form the condensation of polychlorobenzenes had a relation with the concentration of polychlorobenzenes and the chlorine position in the benzene ring.