Effects of dental tissue substructure and size on fracture strengths of lithium disilicate and zirconia ceramics

We aimed to assess the effects of standard resin preparation models with five different thicknesses of occlusal surface on the fracture strengths of zirconia (ZrO2) and lithium disilicate glass ceramics. The specimens of 10 first maxillary molars collected between January 2019 and January 2020 were selected. Standard mathematical models were formed after scanning the resin matrices using software. The full crowns with five different thicknesses of occlusal surface were established, among which the molar specimens prepared by ZrO2 glass ceramic composites alone were assigned into ZrO2 group (n=5, 40 specimens) while those prepared using ZrO2-lithium disilicate glass ceramic composites were allocated into ZTCLDC group (n=5, 40 specimens). When the thickness of glass-ceramic full crowns was 0.5, 0.8, 1.0, 1.2 and 1.5 mm, the fracture load of the specimens in ZTCLDC group was not significantly different from that in ZrO2 group, and there was no significant difference in the three-point flexural strength between ZTCLDC group and ZrO2 group (P>0.05). The fracture toughness was not significantly different between the two groups in the case of the thickness of glass-ceramic full crown at 0.5, 0.8, 1.0, 1.2 and 1.5 mm (P>0.05). The thickness was positively correlated with fracture load, three-point flexural strength and fracture toughness (P<0.05). The fracture strength of lithium disilicate and ZrO2 ceramics is directly proportional to the thickness of ZrO2 and ZTCLDC crowns.

Paeoniflorin mitigates PBC-induced liver fibrosis by repressing NLRP3 formation

ABSTRACT Purpose: To delve into the influence of paeoniflorin (PA) on abating primary biliary cholangitis (PBC)-induced liver fibrosis and its causative role. Methods: Our team allocated the mice to control group, PA group, PBC group and PBC+PA group. We recorded the weight change of mice in each group. We used Masson staining for determining liver fibrosis, immunofluorescence staining for measuring tumor necrosis factor-α (TNF-α) expression, quantitative real-time polymerase chain reaction (qRT-PCR) for assaying related gene expression, as well as Western blot for testing related protein expression. Results: The weight of PBC model mice declined. Twenty-four weeks after modeling, the positive rate of anti-mitochondrial antibody-M2 (AMA-M2) in PBC mice reached 100%. Alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), hydroxyproline (HYP), laminin (LN), procollagen type III (PC III), and malondialdehyde (MDA) contents saliently waxed (p<0.01). Meanwhile, superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activity patently waned (p<0.01). Liver fibrosis levels were flagrantly higher (p<0.01), and TNF-α, NOD-like receptor protein 3 (NLRP3), caspase-1, interleukin-18 (IL-18), and interleukin-1β (IL-1β) protein or gene expression were manifestly up-regulated (p<0.01). PA could restore the weight of PBC mice, strikingly restrain the positive expression of AMA-M2, and down-regulate serum ALP, ALT, AST, HYP, LN, PC III, MDA in PBC mice (p<0.01). PA could also significantly up-regulate SOD and GSH-px levels (p<0.01), down-regulate IL-1β, IL-18, caspase-1, NLRP3, and TNF-α protein or gene expression in PBC mice (p<0.01) and inhibit liver fibrosis levels (p<0.01). Conclusions: PA can reduce PBC-induced liver fibrosis in mice and may function by curbing the formation of NLRP3.

Regulatory effect of hsa-miR-150-5p on malignant behaviors of glioblastoma U-251MG cells by targeting HIF1α / 中国肿瘤生物治疗杂志

@#Objective: To explore the effect and possible mechanisms of has-miR-150-5p targeting HIF1α to regulate malignant biological behaviors of glioblastoma (GBM) U-251MG cells. Methods: Real-time quantitative PCR (RT-PCR) was used to detect the expression of miR-150-5p and hypoxia inducible factor 1 (HIF1α) in U-251MG cells. Luciferase report assay was carried out to verify the biological relationship between miR-150-5p and HIF1α and their biological functions in U-251MG cells. The protein expressions of miR150-5pand HIF1α in U-251MG cells were detected by western blotting. The ability of cell migration was detected by wound healing test and cell invasion ability was detected by transwell test. Results: After miR-150-5p mimic transfection, the mRNA expression of HIF1α was significantly reduced in U-251MG cells (P<0.01). Bioinformatics prediction and luciferase reporter assay demonstrated that miR-150-5p down-regulated HIF1α through directly binding to HIF1α 3’-untranslated region (3’-UTR) (all P<0.05). In U-251MG cells, miR-150-5p over-expression significantly inhibited HIF1α expression, cell invasion and migration (all P<0.05). Conclusion: miR150-5p inhibits cell invasion and metastasis through negative regulation of HIF1α, indicating that miR-150-5p and HIF1α were both potential therapeutic targets for glioblastoma.

Trend analysis of serum uric acid levels in health check-up subjects of Tianjin municipality 2007-2015 / 中华全科医师杂志

Objective To assess the changing trend of serum uric acid (SUA) levles in health check-up subjects of Tianjin municipality 2007-2015.Method Data were collected from 266 043 subjects receiving annual health check-up from 2007 to 2015 in Tianjin municipality.Changing trends of SUA levels and incidence of hyperuricemia were analyzed during the 9 year period.Results From 2007 to 2015 SUA levels in males were increased from (347 ± 73) μmol/L to (373-± 78) μmol/L,while in females were increased from(253 ± 59) μmol/L to (267-± 61) μmol/L.The trend test showed that both for men and woinen the incidence of hypemricemia was increased in each year (men:x2 =270.30,women:x2 =15.10,both P =0.00).The incidence of hyperuricemia by each year was increased more markedly in men than that in women (x2 level:194.80-1 877.00,all P =0.00).The incidence of hyperuricemia in young adults (20-39) was higher than that in middle-ages (40-59),and the latter was higher than that in elderly (＞ 60).For the 7-year (2009-2015) incidence of hyperuricemia in young and middle-aged men,the trend test showed statistical siganificance (x2 level:14.11-233.90,all P =0.00).By contrast,the incidence hyperuricemia in women was increased with aging,and for the 9-year incidence of hyperuricemia in young women,the trend test showed statistical siganificance (x2 level:115.30-480.20,all P =0.00).Conclusion The incidence rates of hyperuricemia are high in Tianjin health check-up subjects,especiallly in young males and old females.There is a time trend of increasing incidence of hyperuricemia in the young and middle-aged subjects.The results indicate that the prevention and control of hyperuricemia in Tianjin are of clinical and social significance.