35 research outputs found

    The effect of BMP9 on inflammation in the early stage of pulpitis

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    Bone morphogenetic protein 9 (BMP9) tends to be associated with various inflammatory responses of diseases, but its relationship with pulpitis remains unknown. Objective: This study aimed to evaluate the effects and mechanisms of BMP9 in pulpitis. Methodology: A rat model of pulpitis was used to evaluate the expression of BMP9, which was also analysed in Porphyromonas gingivalis lipopolysaccharide (Pg-LPS)-stimulated human dental pulp cells (hDPCs). The effects and mechanism of BMP9 on the regulation of inflammatory factors and matrix metalloproteinase-2 (MMP2) were evaluated using real-time quantitative PCR, western blotting, and immunocytofluorescence. Moreover, the migration ability of THP-1 monocyte-macrophages, treated with inflammatory supernate inhibited by BMP9, was previously tested by a transwell migration assay. Finally, a direct rat pulp capping model was used to evaluate in vivo the influence of the overexpression of BMP9 in pulpitis. Results: The expression of BMP9 decreased after 24 h and increased after 3 and 7 d in rat pulpitis and inflammatory hDPCs. The overexpression of BMP9 inhibited the gene expression of inflammatory factors (IL-6, IL-8, and CCL2) and the secretion of IL-6 and MMP2 in Pg-LPS-stimulated hDPCs. The level of phosphorylated Smad1/5 was upregulated and the levels of phosphorylated ERK and JNK were downregulated. The inflammatory supernate of hDPCs inhibited by BMP9 reduced the migration of THP-1 cells. In rat pulp capping models, overexpressed BMP9 could partially restrain the development of dental pulp inflammation. Conclusion: This is the first study to confirm that BMP9 is involved in the occurrence and development of pulpitis and can partially inhibit its severity in the early stage. These findings provided a theoretical reference for future studies on the mechanism of pulpitis and application of bioactive molecules in vital pulp therapy

    Experimental study of dynamic characteristics of an ultra-large jacket offshore wind turbine under wind and wave loads using aero-hydro-structural elastic similarities

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    Owing to the difficulties in the scaled rotor-nacelle assembly (RNA) and support structure design, and alleviation of small scaling effects, the limited dynamic model tests are conducted for the jacket offshore wind turbines (OWTs), which are extensively constructed in the offshore wind farms located in the depth of 40–50 m. To address this limitation, an integrated test method based on aero-hydro-structural elastic similarities is proposed in this study. It comprises a performance-scaled RNA model and a scaled support structure model. A redesigned blade model is adopted in the scaled RNA model to ensure the similarities of aerodynamic thrust loads without modifications of the scaled test winds. Moreover, auxiliary scaled drivetrain and blade pitch control are designed to simulate the operational states of a practical OWT. The scaled model of the OWT support structure is fabricated based on the joint hydro-structural elastic similarity, and the small scaling effects are mitigated by introducing sectional bending stiffness similarities. Subsequently, the dynamic model tests of an ultra-large jacket OWT under wind-only, wave-only, and combined wind and wave conditions are carried out. The accuracy of the fabricated OWT test model is validated based on the recorded responses, and the influence of the dominant frequencies on the dynamic responses of the OWT model is quantitatively evaluated using the wavelet packet-based energy analysis method. Further, the coupling mechanisms of the scaled OWT model under typical wind and wave loads are investigated, and the interactions between the environmental loads and OWT motions are proved

    Experimental Study of Ultra-Large Jacket Offshore Wind Turbine under Different Operational States Based on Joint Aero-Hydro-Structural Elastic Similarities

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    The jacket substructure is generalized for offshore wind farms in the southeastern offshore regions of China. The dynamic characteristics and coupling mechanisms of jacket offshore wind turbines (OWTs) have been extensively investigated using numerical simulation tools. However, limited dynamic model tests have been designed and performed for such types of OWTs. Therefore, the coupling mechanisms of jacket OWTs that are determined using numerical methods require further validation based on experimental tests. Accordingly, an integrated scaled jacket OWT physical test model is designed in this study. It consists of a scaled rotor nacelle assembly (RNA) and support structure model. For the scaled RNA model, a redesigned blade model is adopted to ensure the similarity of the aerodynamic thrust loads without modifying the scaled test winds. Auxiliary scaled drivetrain and blade pitch control system models are designed to simulate the operational states of a practical OWT. The scaled model of the OWT support structure is fabricated on the basis of the joint hydro-structural elastic similarities. A sensor arrangement involving a three-component load cell and acceleration sensors is used to record the OWT thrust loads and model motions, respectively. Then, dynamic model tests under typical scaled wind fields are implemented. Furthermore, the coupling mechanisms of the OWT model under various test winds are investigated using the wavelet packet method, and the influences of inflow winds, operational states, and mechanical strategies are introduced

    The effects and potential applications of concentrated growth factor in dentin–pulp complex regeneration

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    Abstract The dentin–pulp complex is essential for the long-term integrity and viability of teeth but it is susceptible to damage caused by external factors. Because traditional approaches for preserving the dentin–pulp complex have various limitations, there is a need for novel methods for dentin–pulp complex reconstruction. The development of stem cell-based tissue engineering has given rise to the possibility of combining dental stem cells with a tissue-reparative microenvironment to promote dentin–pulp complex regeneration. Concentrated growth factor, a platelet concentrate, is a promising scaffold for the treatment of dentin–pulp complex disorders. Given its characteristics of autogenesis, convenience, usability, and biodegradability, concentrated growth factor has gained popularity in medical and dental fields for repairing bone defects and promoting soft-tissue healing. Numerous in vitro studies have demonstrated that concentrated growth factor can promote the proliferation and migration of dental stem cells. Here, we review the current state of knowledge on the effects of concentrated growth factor on stem cells and its potential applications in dentin–pulp complex regeneration

    No Association between Elevated 2-h Postprandial Blood Glucose Levels and Functional Outcomes of Small-Artery Occlusion in Patients with Diabetes

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    BackgroundThe association between 2-h postprandial blood glucose level (2hPBG) and functional outcomes in patients with small-artery occlusion (SAO) is poorly understood. We aimed to explore the relationship between 2hPBG levels and functional outcomes in SAO patients with diabetes.MethodsWe retrospectively analyzed 174 diabetic patients diagnosed with SAO, and 2hPBG values were classified into four groups according to quartiles (<8.90, 8.90 to <12.16, 12.16 to <15.14, and ≥15.14 mmol/L), or according to clinical glycemic recommendations for adults with diabetes (<10 and ≥10 mmol/L, respectively). The relationship between 2hPBG levels and modified Rankin Scale (mRS) scores was assessed using univariate and multivariate analyses.ResultsAmong all patients with SAO, there were 139 patients with favorable outcomes and 35 patients with poor outcomes. National Institutes of Health Stroke Scale scores were significantly different according to mRS scores (P < 0.001) in both the univariate and multivariate analyses. The binary logistic regression analyses showed that compared with the lowest quartile (<8.90 mmol/L), elevated 2hPBG levels (8.90 to <12.16, 12.16 to <15.14, and ≥15.14 mmol/L) were not associated with mRS scores after adjusting for multiple confounding factors. Compared with patients with 2hPBG levels <10 mmol/L, those with 2hPBG levels ≥10 mmol/L did not have a significant risk of poor outcome after adjusting for confounders. Meanwhile, the negative results appeared in the ordinal logistic regression of 2hPBG levels and 3-month functional outcomes.ConclusionElevated 2hPBG levels were not associated with unfavorable functional outcomes 3 months after stroke onset in SAO patients with diabetes

    Eye movement evidence in investigative identification based on experiments

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    Investigative identification is a routine criminal investigative procedure, the results of which can be used as evidence in litigation. However, some suspects often deny their involvement in the case, and some witnesses may withhold information or misrepresent it, all of which may lead to a miscarriage of justice. This study created a stressful environment and conducted a simulated crime experiment to explore whether eye movement data can be an effective feature for distinguishing perpetrators, innocents, and insiders. The eye movement features—such as the total fixation duration, number of fixations, and first fixation duration—within an area of interest were collected from 83 participants sorted into informed, involved, and innocent groups. The results revealed the following: (1) compared with the object and scene stimuli, subjects with different identities were more likely to exhibit significant differences in eye movement data for the involved and irrelevant portraits. The total fixation duration and the number of fixations can provide a reference for judging whether someone is involved in a case, and the first fixation duration effect was not obvious. (2) Using machine learning algorithms to predict subjects’ identities through eye movement features, it was demonstrated that the involved portrait-object-scene model had the best predictive effect. (3) Multiple algorithmic models were used to distinguish subjects’ identities, and the highest accuracy of 92.7% was achieved for the informed × innocent group, 88% for the innocent × suspect group (including the informed and involved groups), and 84.5% for the involved group. The eye movement analysis method can provide a reference for criminal investigators to distinguish between the perpetrator, insider, and innocent, and offer a novel approach to determining the direction of further investigation and uncovering and verifying case clues

    Corrosion behavior of heat-resistant stainless steel in high temperature molten glass

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    The development of the nuclear industry and nuclear energy have prompted studies focusing on disposal of nuclear waste in a green and safe way. The use of metal containers to fill glass solidified nuclear waste and then landfill is currently the dominant way in waste disposal. However, the high temperature corrosion caused by the high temperature molten glass on the surface of the metal container becomes an important factor accelerating the failure of the container. Therefore, an in-depth understanding of the corrosion behavior of metals in high temperature molten glass is necessary to ensure the safety of disposal of nuclear waste.The S30815 heat-resistant stainless steel was selected as the research object, and the corrosion morphology, composition and phase structure of the S30815 heat-resistant stainless steel kept in 1100 ℃ molten glass for different time were deeply analyzed. The results show that the molten glass corrodes inward along the grain boundary into the matrix and molten glass gradually replaces the steel by occupying the grain boundary and further penetrates the grains to form corrosion pits. Cr and Si elements in the heat-resistant stainless steel diffuse into the molten glass during corrosion, resulting in a decrease of content at the surface, and finally promote the transformation of metal surface from austenite to martensite. The corrosion of heat-resistant stainless steel by molten glass is alkaline dissolution. A continuous and stable oxide film cannot be formed on the surface, which means the corrosion will continue with the extension of holding time

    Highly Proliferative Immortalized Human Dental Pulp Cells Retain the Odontogenic Phenotype when Combined with a Beta-Tricalcium Phosphate Scaffold and BMP2

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    Human dental pulp cells (HDPCs) play a vital role in dentin formation and reparative dentinogenesis, which indicated their potential application in regenerative medicine. However, HDPCs, which can only be obtained from scarce human pulp tissues, also have a limited lifespan in vitro, and stem cells usually lose their original characteristics over a large number of passages. To overcome these challenges, we successfully immortalized human dental pulp cells using the piggyBac system which was employed to efficiently overexpress the SV40 T-Ag, and we then comprehensively described the cell biological behavior. The immortalized human dental pulp cells (iHDPCs) acquired long-term proliferative activity and expressed most HDPC markers. The iHDPCs maintained multiple differentiation potential and could be induced to differentiate into chondrogenic, osteogenic, and adipogenic cells in vitro. We also proved that the iHDPCs gained a stronger ability to migrate than the primary cells, while apoptosis was inhibited. Furthermore, highly proliferative iHDPCs displayed no oncogenicity when subcutaneously implanted into athymic nude mice. Finally, iHDPCs exhibited odontogenic differentiation ability and secreted dentin sialophosphoprotein (DSPP) when combined with a beta-tricalcium phosphate scaffold and bone morphogenetic protein-2 (BMP2) in vivo. Conclusively, the established iHDPCs are a valuable resource for mechanistic study of dental pulp cell differentiation and dental pulp injury repair, as well as for applications in tooth regeneration
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