Cleaning Oily Sludge Using Colloidal Gas Aphrons: Optimizing Process Conditions and Analyzing Mechanisms.

Colloidal gas aphrons (CGAs) are applied in pollutant removal due to their large specific surface area and high surface activity. The structure and properties of the prepared CGAs were investigated in the process of oil removal from oily sludge. The prepared CGAs had a liquid film thickness was 5-10 µm with high stability. CGA interfacial tension was as low as 3.157 mN/m. Then it was found that the oil removal rate of CGAs was higher than that of chemical treatments, showing that CGAs could increase the mass transfer surface area and provide additional attachment sites for pollutants, enhancing the oil removal. The treatment conditions of the oil removal were optimized through response surfaces, showing that under optimal treatment conditions, the oil removal rate of oily sludge reached 96.07%. Additionally, the interaction between surfactant concentration and temperature was the most significant of all of the influencing factors. The behavior and mechanism of CGAs in the cleaning process of oily sludge were further investigated using an inverted fluorescence microscope, SEM, FTIR, and two-dimensional fluorescence spectrometer, showing that pollutants transferred from the liquid film surface of CGAs to the inside the film, and CGAs could specifically adsorb negatively charged organic compounds and aromatic hydrocarbons. The results show that CGAs achieved liquid membrane solubilization. Many negatively charged organic compounds and aromatic hydrocarbons are adsorbed onto the CGAs liquid membrane surface via electrostatic and hydrophobic interactions and then migrated to the hydrophobic layer of the CGAs liquid membrane due to the distribution effect, thus enabling rapid pollutant migration between solid and liquid phases.

A short-term analysis of the modification process of the plaque microbial community before and after treatment in children with S-ECC / 口腔疾病防治

Objective @# To explore from the perspective of microorganisms the changes in plaque microbial community of children with severe early childhood caries (S-ECC) before and 3 months after dental treatment. Meanwhile to show the effect of treatment on the maintenance of long- term caries-free state. @*Methods@# S-ECC children completed dental treatment under general anesthesia. We collected plaque from caries-free dental surfaces before treatment (caries, C) and at the postoperative follow-up review time points of 7 days (C-7D), 1 month (C-1 M), and 3 months (C-3 M). We included caries-free children (caries free, CF) as the control group to analyze the dynamic modification process of the plaque microbial community in the short-term pre- and postdental treatment.@*Results@#Species clustering analysis showed that the compositions of the microbial communities of the S-ECC and CF groups were highly similar. The α diversity index was not statistically significant (P>0.05). From the analysis of the relative abundance, Leptotrichia spp. and Aggregatibacter spp. decreased after treatment compared with before treatment (P<0.05). Streptococcus sanguinis in the C-7D group increased compared with that in the C group and gradually decreased within 3 months. Veillonella spp., Actinomyces spp., Allprevotella spp., Capnocytophaga spp., and Streptococcus mutans differed between the C and CF groups (P<0.05), Streptococcus mutans did not differ significantly between the C-7D and C-1 M groups and the CF group after treatment, while C-3 M showed an increase compared with the CF group (P<0.01). @*Conclusion@#The rapid change in the structure of the flora of children with S-ECC after treatment. The plaque microbial community structure in a caries-free state gradually starts to be established 1-3 months after treatment. There is a "core microbiota" in the oral plaque community that jointly maintains microecological stability. Veillonella spp., Allprevotella spp. and Streptococcus mutans have potential as possible microbial markers.

Research progress on the relationship between the changes in microbial community composition of plaque and dental caries in children / 口腔疾病防治

@#Among many factors affecting dental caries, bacteria are its initiating factor. From the perspective of ecological plaque hypothesis, the application of modern molecular biology methods enable scholars to deeply explore the relationship between the microbial population distribution, biodiversity, microbial community changes of dental plaque biofilm and the occurrence of dental caries in children. The decrease in microflora diversity is closely related to the occurrence of dental caries, which can be detected as early as 6 months before the occurrence of dental caries, providing an important basis for caries monitoring and caries risk assessment. Differential bacteria such as Lactobacillus and Veillonella may be used as biomarkers of caries in children to judge the risk of caries in children. However, current studies have shown that the dominant bacteria in the microbial community structure vary in different processes of caries occurrence and development, that the interaction between different flora is still not clear, and that the specific cariogenic mechanism of the oral plaque microbial community in the process of caries occurrence and development has not been clarified. Further research is still needed to explore the changes in plaque microbial diversity and composition during the development of dental caries and to screen specific dental caries biomarkers. This paper also summarizes the related research findings.

MiR-495/IGF-1/AKT Signaling as a Novel Axis Is Involved in the Epithelial-to-Mesenchymal Transition of Oral Squamous Cell Carcinoma.

PURPOSE: Increasing evidence suggests that aberrant expression of miR-495 is associated with the progression of various cancers. The aim of this study was to investigate the function and underlying mechanism of miR-495 in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: OSCC specimens and oral cancer cell lines, as well as the OSCC microRNA expression profile from the Gene Expression Omnibus database, were used to detect the expression of miR-495 in OSCC. Cell proliferation, migration, and invasion assays were performed to analyze the function of miR-495. Bioinformatics and luciferase reporter assays were used to identify the target gene of miR-495. Pearson analysis was carried out to investigate the correlation between miR-495 and insulin-like growth factor 1 (IGF1) or AKT levels. Transfection of pcDNA3.1 vector and small interfering RNA was performed to overexpress or downregulate the expression of IGF1. OSCC xenografts in mice were constructed to validate the function and mechanism of miR-495 in vivo. RESULTS: MiR-495 was downregulated in OSCC tissues and cell lines, and it markedly inhibited cell proliferation, migration, and invasion, as well as epithelial-to-mesenchymal transition (EMT)-related proteins of OSCC cells. IGF1 was identified as a direct target gene of miR-495. Besides, AKT was confirmed to be regulated by miR-495/IGF-1 signaling, and miR-495 was negatively correlated with IGF1 and AKT in OSCC. In vivo, miR-495 inhibited the growth and EMT-related proteins of OSCC xenografts in mice. CONCLUSIONS: The miR-495/IGF-1/AKT signaling axis played a tumor-suppressive role in OSCC by regulating cell proliferation, invasion, and migration, as well as EMT.

Increased interleukin 1α and interleukin 1ß expression is involved in the progression of periapical lesions in primary teeth.

BACKGROUND: Interleukin 1 (IL-1) is involved in bone resorption. However, the role of IL-1 in periapical lesions characterized by periapical bone destruction in primary teeth has not yet been fully elucidated. This study aimed to detect the distribution and expression of IL-1 in periapical lesions in primary teeth and assess the relationship between the cytokines and the degree of inflammatory cell infiltration. METHODS: A total of 106 chronic periapical lesions in primary teeth were harvested. Haematoxylin and eosin (H&E) staining was used to determine the histological type and the inflammatory cell infiltration grade (mild, moderate, and severe), and immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution and expression of IL-1α and IL-1ß. RESULTS: Of the 106 chronic periapical lesion samples, there were 85 cases of periapical granuloma, accounting for 80.19% of the total samples, and 21 cases of radicular cysts, accounting for 19.81%; no cases of abscess were detected. Immunohistochemistry results showed that both IL-1α and IL-1ß were expressed in periapical granulomas and cysts. ELISA results showed that IL-1α and IL-1ß levels were higher in the periapical granuloma group than in the radicular cyst and normal control groups (P < 0.05). In the periapical granuloma group, IL-1α and IL-1ß were detected at higher levels in the severe inflammatory cell infiltration subgroup than in the mild-inflammatory cell infiltration subgroup (P < 0.05), and IL-1ß expression was also higher in the moderate inflammatory cell infiltration subgroup than in the mild inflammatory cell infiltration subgroup (P < 0.01). A significant positive correlation was observed between the protein expression levels of IL-1α and IL-1ß and the inflammation grade in periapical granulomas from primary teeth (P < 0.05). CONCLUSION: Expression levels of the cytokines IL-1α and IL-1ß in periapical granulomas from primary teeth increased with increasing inflammatory severity and appeared to be a contributing factor to the progression of periapical lesions.

Clinical study of root canal numbers in maxillary second primary molars / 口腔疾病防治

Objective@#To investigate the root canal numbers of maxillary second primary molars.@*Methods @#216 max illary second primary molars from 204 children aged 3-8 years old were selected. All the teeth need to do the root canal therapy. After opening the pulp chamber, the root canal were examined and determined with small size K file and 17％ethylene diaminetetraacetic acid (EDTA). Hand instruments were used for root canal preparation and then zinc-oxide iodoform paste was used for filling. @*Results @#216 maxillary second p rimary molars, 122 teeth had three root canals(56.5%), and 94 teeth had four root canals (43.5%). The incidence of second mesiobuccal canal (MB2) was 41.2%. There was no correlation between the incidence of the MB2 canal and gender and tooth position. @*Conclusion@# The root canals of maxillary second primary molars had more variations, and there was a high incidence of the second mesiobuccal canal.

Preliminary molecular analysis of bacterial composition in periapical lesions with primary endodontic infections of deciduous teeth.

BACKGROUND: The bacterial composition of periapical lesions in deciduous teeth has not been well documented. This study was designed to explore the bacterial compositions, especially the dominant bacteria in periapical lesions using 16S rRNA sequencing. METHODS: Tissue samples were collected from 11 periapical lesions in deciduous teeth with primary endodontic infections. DNA was extracted from each sample and analyzed using 16S rRNA cloning and sequencing for the identification of bacteria. RESULTS: All DNA samples were positive for 16S rRNA gene PCR. One hundred and fifty-one phylotypes from 810 clones were identified to eight phyla, and each sample contained an average of 25.9 phylotypes. In addition, 59 phylotypes were detected in more than two samples, and Fusobacterium (F.) nucleatum (8/11), Dialister (D.) invisus (8/11), Campylobacter (C.) gracilis (7/11), Escherichia (E.) coli DH1 (6/11), Aggregatibacter (A.) segnis (6/11), and Streptococcus (S.) mitis (6/11) were the most prevalent species. Furthermore, 45 as-yet-uncultivated phylotypes were also identified. CONCLUSIONS: Chronic periapical lesions in deciduous teeth contained polymicrobial infections. F. nucleatum, D. invisus, C. gracilis, E. coli DH1, A. segnis, and S. mitis were the most prevalent species detected by 16S rRNA sequencing.