Preparation and Performance Study of Rapid Repair Epoxy Concrete for Bridge Deck Pavement.

With the rapid development of bridge construction, the service life of bridges and traffic volume continue to increase, leading to the gradual appearance of diseases such as potholes and cracks in bridge deck pavements under repeated external loads. These issues severely impact the safety and service life of bridges. The repair of bridge deck potholes and cracks is crucial for ensuring the integrity and safety of bridge structures. Rapid repair materials designed for this purpose play a critical role in effectively and efficiently addressing these issues. In order to address the issues of pavement diseases, this study focuses on the rapid repair of epoxy concrete for bridge deck pavements and its performance is studied using experimental methods. Firstly, carbon black, rubber powder, and other materials were used to improve the elastic modulus and aging resistance of the epoxy concrete. Secondly, the addition of solid asphalt particles provided thermal sensitivity to the repair material. Finally, various properties of the rapid repair epoxy concrete for bridge deck pavements were tested through experiments including compressive strength testing, elastic modulus measurement, thermal sensitivity testing, and anti-UV aging testing. The experimental results show that adding carbon black and rubber powder reduces the elastic modulus of epoxy concrete by 25% compared to normal epoxy concrete, while increasing its aging resistance by 1.8%. The inclusion of solid asphalt particles provided thermal sensitivity to the repair material, contributing to better stress coordination between the repair material and the original pavement material under different temperature conditions. The epoxy concrete has early strength, toughness, and anti-aging properties, making it suitable for rapid repair of bridge deck pavement.

Silica nanoparticles containing nano-silver and chlorhexidine to suppress Porphyromonas gingivalis biofilm and modulate multispecies biofilms toward healthy tendency.

Objectives: This research first investigated the effect of mesoporous silica nanoparticles (nMS) carrying chlorhexidine and silver (nMS-nAg-Chx) on periodontitis-related biofilms. This study aimed to investigate (1) the antibacterial activity on Porphyromonas gingivalis (P. gingivalis) biofilm; (2) the suppressing effect on virulence of P. gingivalis biofilm; (3) the regulating effect on periodontitis-related multispecies biofilm. Methods: Silver nanoparticles (nAg) and chlorhexidine (Chx) were co-loaded into nMS to form nMS-nAg-Chx. Inhibitory zone test and minimum inhibitory concentration (MIC) against P. gingivalis were tested. Growth curves, crystal violet (CV) staining, live/dead staining and scanning electron microscopy (SEM) observation were performed. Biofilm virulence was assessed. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and Quantitative Real Time-PCR (qPCR) were performed to validate the activity and composition changes of multispecies biofilm (P. gingivalis, Streptococcus gordonii and Streptococcus sanguinis). Results: nMS-nAg-Chx inhibited P. gingivalis biofilm dose-dependently (p<0.05), with MIC of 18.75 µg/mL. There were fewer live bacteria, less biomass and less virulence in nMS-nAg-Chx groups (p<0.05). nMS-nAg-Chx inhibited and modified periodontitis-related biofilms. The proportion of pathogenic bacteria decreased from 16.08 to 1.07% and that of helpful bacteria increased from 82.65 to 94.31% in 25 µg/mL nMS-nAg-Chx group for 72 h. Conclusions: nMS-nAg-Chx inhibited P. gingivalis growth, decreased biofilm virulence and modulated periodontitis-related multispecies biofilms toward healthy tendency. pH-sensitive nMS-nAg-Chx inhibit the pathogens and regulate oral microecology, showing great potential in periodontitis adjunctive therapy.

Influence of Interface Modification on the Moisture Absorption and Thermal Resistance of Ramie Fiber/Degradable Epoxy Composites.

Natural fiber/degradable epoxy composites have received much attention for their advantages of low carbon emissions, low environmental pollution, and utilization of renewable resources. However, the poor interfacial bonding strength and inferior moisture resistance of natural fiber/degradable epoxy composites restrict their application areas. In order to improve the moisture and heat resistance of natural fiber/degradable epoxy resin-based composites, this study modified the surfaces of ramie fibers with hydroxylated carbon nanotubes, silane coupling agents, and sodium hydroxide, respectively. Three types of modified ramie fiber/degradable epoxy composites, namely F-CN-DEP, F-Si-DEP, and F-OH-DEP, were prepared using a winding forming process. The water absorption rate and short-beam shear strength of the materials were tested under different environments, and the fiber morphology and thermal-mechanical properties of the materials were investigated by scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). The results show that F-CN-DEP exhibited the lowest moisture absorption rate; the highest shear strength, of 43.8 MPa; and a glass transition temperature (Tg) of 121.7 °C. The results demonstrate that carbon nanotubes on the fiber surface can improve the interfacial stability of ramie fiber/degradable epoxy composites in humid and hot environments. These results give guidelines for the development of natural fiber/degradable epoxy composites.

Lightweight ZnO/Carbonated Cotton Fiber Nanocomposites for Electromagnetic Interference Applications: Preparation and Properties.

Electromagnetic wave pollution has become a significant harm posed to human health and precision instruments. To shelter such instruments from electromagnetic radiation, high-frequency electromagnetic interference (EMI) shielding materials are extremely desirable. The focus of this research is lightweight, high-absorption EMI shielding composites. Simple aqueous dispersion and drying procedures were used to prepare cotton fiber (CF)-based sheets combined with various zinc oxide (ZnO) contents. These composites were carbonated in a high-temperature furnace at 800 °C for two hours. The obtained CF/ZnO samples have densities of 1.02-1.08 g/cm3. The EMI shielding effectiveness of CF-30% ZnO, CF-50% ZnO, and CF-70% ZnO reached 32.06, 38.08, and 34.69 dB, respectively, to which more than 80% of absorption is attributed. The synergetic effects of carbon networks and surface structures are responsible for the high EMI shielding performance; various reflections inside the interconnected networks may also help in improving their EMI shielding performance.

Effects of rice-prawn (Macrobrachium nipponense) co-culture on the microbial community of soil.

In the Lixiahe region of China, co-culture has been rapidly promoted in flooded paddy fields owing to its ecological and economic benefits. Rice-prawn co-culture can reduce the damage of crab and shrimp to rice growth and paddy field and substantially change the soil microbial community and soil fertility. In this study, we compared changes in the soil microbial community and soil fertility in waterlogged paddies under conventional rice culture (CR), rice-prawn (Macrobrachium nipponense) co-culture (RP), and pond culture (PC). The microbial abundance in RP was significantly higher than that in CR. RP soil microbial diversity was significantly higher than PC soil microbial diversity. The dominant bacteria in RP soil were Proteobacteria, Chloroflexi, and Bacteroidetes. Compared with those in CR, total organic matter (TOM) and total nitrogen in RP were relatively stable, available potassium and available phosphorus (AP) decreased, and other indicators increased significantly. Soil fertility significantly benefited from co-culture, with total organic carbon (TOC) increasing. Interactive relationship analysis showed that TOM, TOC, AP, and NH4+-N were the main factors affecting the microbial community. Co-occurrence network analyses showed that network modularity increased with co-culture, indicating that a unique soil microbial community formed under co-culture, improving the adaptability and tolerance to co-culture. Thus, RP is a suitable culture method for this commercially important species. The results of this study can inform the practical operation of fertilizer use and sustainable development of rice-prawn aquaculture systems. KEY POINTS: • Microbial abundance and diversity increased under rice-prawn co-culture. • Co-culture significantly improved soil fertility, with an increase in TOC. • Rice-prawn co-culture is an ecologically suitable culture method for prawns.

TRPM2-AS promotes the malignancy of osteosarcoma cells by targeting miR-15b-5p/PPM1D axis.

Osteosarcoma (OS) is a malignant tumor with a low survival rate and a high incidence rate worldwide. Although research has reported the involvement of long non-coding RNAs (lncRNAs) in the pathogenesis of OS cells, the role of TRPM2-AS, miR-15b-5p, and PPM1D in OS progression remains unclear. This study aimed to examine the interaction of the TRPM2-AS/miR-15b-5p/PPM1D axis in OS cells to gain new insights into the molecular mechanism and pathogenesis of OS. After performing in vitro functional assays, we discovered that TRPM2-AS was overexpressed in OS cells. TRPM2-AS silencing impaired OS cell viability, proliferation, and migration, while it induced apoptosis in OS cells in vitro. Our experimental analysis also revealed that PPM1D is a direct target of miR-15b-5p. TRPM2-AS silencing was found to reverse the tumorigenic effect of the miR-15b-5p inhibitor, while the miR-15b-5p inhibitor restored the inhibition of OS caused by silencing PPM1D. Moreover, our findings revealed that miR-15b-5p exerted its tumor-suppressive role by directly targeting PPM1D. In conclusion, this study suggests that TRPM2-AS could promote OS cell malignancy by sponging miR-15b-5p/PPM1D axis.

Oral mosapride can provide additional anti-emetic efficacy following total joint arthroplasty under general anesthesia: a randomized, double-blinded clinical trial.

BACKGROUND: We sought to determine (1) whether the addition of prophylactic oral mosapride to a protocol including dexamethasone and ondansetron further reduces postoperative nausea and vomiting (PONV) compared with ondansetron alone or the combination of both; (2) whether preemptive application of oral mosapride provides additional clinical benefits for bowel function and appetite, thus improving functional recovery. METHODS: We randomized 240 patients undergoing total hip and knee arthroplasty to receive placebo (Control, n = 80), dexamethasone (10 mg) before anesthesia induction (Dexa, n = 82), or dexamethasone (10 mg) before anesthesia induction as well as oral mosapride (5 mg) before and after surgery (Mosa+Dexa, n = 78). Patients were assessed at 0-6, 6-12, 12-24, and 24-48 h postoperatively. Primary outcomes were incidence and severity of PONV as well as complete response. Secondary outcomes were appetite, time until first defecation and ambulation, patient satisfaction score, and length of hospital stay. RESULTS: Mosa+Dexa patients showed significantly lower incidence of nausea at 6-12 h (3.8%) and over the entire evaluation period (6.4%), as well as a higher rate of complete response (89.7%) than other patients. Mosa+Dexa patients required less time to achieve first defecation and ambulation, they were hospitalized for shorter time, and they were more satisfied with clinical care. CONCLUSION: Addition of oral mosapride further reduced incidence of PONV, especially postoperative nausea, during 6-12 h postoperatively. Moreover, preemptive application of oral mosapride can further improve appetite, bowel function, ambulation and length of hospital stay. TRIAL REGISTRATION: The study protocol was registered at the Chinese Clinical Trial Registry ( ChiCTR1800015896 ), prospectively registered on 27/04/2018.

In Silico Prediction of Metabolic Epoxidation for Drug-like Molecules via Machine Learning Methods.

Epoxidation is one of the reactions in drug metabolism. Since epoxide metabolites would bind with proteins or DNA covalently, drugs should avoid epoxidation metabolism in the body. Due to the instability of epoxide, it is difficult to determine epoxidation experimentally. In silico models based on big data and machine learning methods are hence valuable approaches to predict whether a compound would undergo epoxidation. In this study, we collected 884 epoxidation data manually from various sources, and finally got 829 unique sites of epoxidation. Three types of molecular fingerprints with different lengths (1024, 2048 or 4096 bits) were used to describe the reaction sites. Six machine learning methods were used to build the classification models. The training set and test set were randomly divided into 8 : 2, and 54 models were constructed and evaluated. Four best models were selected for feature selection. The features were then chosen and verified by external validation set. The resulted optimal model had the accuracy and AUC (area under the curve) values at 0.873 and 0.944 for the test set, 0.838 and 0.987 for the external validation set, respectively. The models built in this study could accurately predict whether a compound will undergo epoxidation and which part is most susceptible to epoxidation, which is of great significance for drug design.

Effect of Ginsenoside Rg1 on the intervertebral disc degeneration rats and the degenerative pulposus cells and its mechanism.

OBJECTIVE: To explore the effect of ginsenoside Rg1 on intervertebral disc degeneration (IVDD) in vivo and in vitro and its mechanism. METHODS: 60 rats were underwent surgery to construct rat models of IVDD and divided in the sham group, model group and gradient G-Rg1 groups (10 mg/kg/d, 20 mg/kg/d and 40 mg/kg/d).The change of histology was observed by HE staining, the water content and the expression of ß-catenin in IVD were detected. Rat nucleus pulposus cells(NPCs) were isolated from IVDD rats and divided in D-NPCs group, and gradient G-Rg1 groups(20 µg/ml, 50 µg/ml and 100 µg/ml).The cell proliferation activity, cell apoptosis rate,the expression of proteins related to ECM and Wnt/ß-catenin were detected respectively, Finally the agonist of Wnt/ß-catenin pathway LiCl was used for reversed experiments. RESULTS: In vivo, G-Rg1 treatment could improve the structural disorganization, low water content, NPCs number and aggrecan and collagenⅡ expression in IVD and down-regulate the expression of ß-catenin. In vitro NPCs, G-Rg1 treatment could improve the low cell proliferation, high apoptosis rate and low expression of aggrecan and collagenⅡ in degenerative NPCs in a dose-dependent manner.G-Rg1 treatment could down-regulate the expression of proteins related to ß-catenin signal and LiCl could reverse the increase of cell proliferation and ECM synthesis, decrease of apoptosis of degenerative NPCs induced by G-Rg1. CONCLUSION: G-Rg1 could promote ECM synthesis of degenerative NPCs and inhibiting its apoptosis, improve the IVDD via inhibiting the Wnt/ß-catenin pathway.

Insights into the interaction mechanisms of estrogen-related receptor alpha (ERRα) with ligands via molecular dynamics simulations.

Estrogen-related receptor alpha (ERRα), a member of nuclear receptors (NRs), participates in energy metabolism. Recent experiments identified that several agonists to increase the activity of ERRα, which have a therapeutic effect in improving insulin sensitivity and lowering blood glucose levels. However, the detailed molecular mechanism about how the ligands affect the structure of ERRα remains elusive. To better understand the conformational change of ERRα complexed with agonists and inverse agonists, unbiased molecular dynamics (MD) simulations were performed on the ligand binding domain of ERRα (ERRα-LBD) bound with different ligands. According to the results, the ERRα-agonist interactions were more stable in the presence of the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α). More importantly, we observed that the binding of inverse agonists would decrease the stability of helix 12 (H12) of ERRα. Moreover, we suggested that Phe232 and Phe414 should be key residues in the interaction pathway from ligands to H12, which provided a possible explanation about how ligands impact the structure of ERRα. These results would provide insights into the design of novel and efficient agonists of ERRα to treat metabolic diabetes.Communicated by Ramaswamy H. Sarma.