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In this work, MgO-coated carbon nanotubes (MgO@CNTs) were synthesized via the co-deposition technique. The samples of MgO@CNTs were treated by using the high power ultrasonic vibration with a long time to verify their structural stability. Microstructure of the CNTs and MgO@CNTs was characterized by using the FI-IT spectra analysis, scanning electron microscope and transmission electron microscope. The experiment result reveals that the high power ultrasonic vibration and the long-time ultrasonic-treatment can easily cut off the CNTs, while the MgO nanoparticles are still tightly adsorbed on the surface of CNTs without removing away from the surface of CNTs by the ultrasonic vibration. It means that MgO@CNTs is a novel reinforcement for the Mg-based composite because the MgO nanoparticles and CNTs have formed a good interface bonding with high stability. Simultaneously, the stable interfacial bonding between MgO and CNTs is explained by the first- principle calculation.

The challenge of low adhesion between the wheel and the rail constrains the advancement of train braking technologies, resulting in sliding during braking, increased braking distances, and even operational safety incidents. Low adhesion arises from the contamination of the rail surface by a third body, such as water or oil, significantly reducing adhesion. However, experimental studies have found that wheel-rail adhesion coefficient under water lubrication conditions possesses recovery capability. In scenarios characterized by low adhesion in water lubrication conditions, a secondary rise in adhesion occurs when substantial wheel-rail sliding is present. This paper focuses on numerically modeling the unique phenomenon of adhesion recovery during large-sliding processes under water lubrication conditions. Considering the notable differences in frictional heating during wheel sliding, as opposed to pure rolling conditions, we construct a wheel-rail contact model under mixed lubrication conditions that incorporates the solid–liquid coupled heat transfer effect. This model achieves stable solutions for the wheel-rail contact relationship and the temperature at the wheel-rail interface. The impacts of velocity, axle load, water temperature, and slide ratio on the adhesion recovery phenomenon are discussed, revealing the underlying mechanism of adhesion recovery during large sliding processes. Finally, brake adhesion tests under water lubrication conditions are conducted on a scaled test rig to validate the proposed theoretical model. [ABSTRACT FROM AUTHOR]

Background The immunopathological mechanisms underlying neurosyphilis remain incompletely elucidated, and the diagnosis of neurosyphilis presents challenges. Methods We used an antibody microarray to detect 640 proteins in cerebrospinal fluid (CSF) samples collected from 6 patients with non-neurosyphilis and 10 with neurosyphilis. The levels of CSF CXCL1, CXCL8, G-CSF, LCN2, MMP8, and MMP9 in 46 patients with non-neurosyphilis, 51 with untreated neurosyphilis, and 31 posttreatment for neurosyphilis were quantified using enzyme-linked immunosorbent assay. The associations between the levels of these proteins and clinical parameters in neurosyphilis were evaluated using Spearman analysis, and the diagnostic performance of these proteins in neurosyphilis was assessed using receiver operating characteristic curve. Results A total of 102 differentially expressed proteins between neurosyphilis and non-neurosyphilis were identified. The levels of significantly elevated neutrophil-associated proteins (CXCL1, CXCL8, G-CSF, LCN2, MMP8, and MMP9) in neurosyphilis positively correlated with white blood cell counts, rapid plasma regain (RPR) titer, and protein concentration in CSF. The combination of CSF CXCL8, MMP9, and LCN2 yielded an area under the curve of 0.92 for diagnosing neurosyphilis, surpassing that of CSF RPR. Conclusions CXCL1, CXCL8, G-CSF, LCN2, MMP8, and MMP9 could be associated with central nervous system damage of neurosyphilis. The combination of CSF CXCL8, MMP9, and LCN2 is a promising biomarker for diagnosing neurosyphilis. [ABSTRACT FROM AUTHOR]

Background: Poly-victimization (PV) not only threatens physical and mental health but also causes a range of social problems. Left-behind children in rural areas are more likely to experience PV problems. However, there have been fewer studies on PV among rural children, and even fewer intervention studies. Objective: The difference-in-differences method was employed to analyze the impact of intervention measures, based on the theory of planned behavior, on PV among left-behind children in rural areas. Methods: The study subjects were left-behind children from six middle schools in two cities in southern China, who completed the baseline survey from 2020 to 2021. They were divided into a control group and an intervention group, each consisting of 228 cases, based on their schools. Before and after the intervention, the Self-made victimization-related knowledge, attitude, and practice questionnaire, Poly-victimization scale, and Middle school students' coping style scale were used to evaluate the victimization-related KAP(knowledge, attitude, and practice), victimization occurrence, and coping styles of left-behind children, respectively. Stata 15.0 was used to establish a difference-in-differences regression model to analyze the impact of the intervention measures on poly-victimization and coping styles. Results: Mixed Anova revealed that after the intervention, the KAP scores of the intervention group were significantly higher than those of the control group (p < 0.05). After the intervention, the incidence of child victimization in the intervention group dropped to 9.60% (n = 22), lower than in the baseline survey, with a statistically significant difference (p < 0.01). The incidence of PV among children in the intervention group was lower than that in the control group, with the difference being statistically significant (p < 0.01). The net reduction in the incidence of PV among children was 21.20%. After the intervention, the protection rate for preventing PV among children was 73.33%, and the effect index was 3.75. The intervention improved children's coping styles, problem-solving, and help-seeking, while reducing negative coping styles such as avoidance and venting, with the differences being statistically significant (p < 0.05). Conclusion: Intervention measures based on the theory of planned behavior reduce the occurrence of PV among left-behind children, and the intervention effects on different types of victimization are also different. [ABSTRACT FROM AUTHOR]

The aim is to identify latent classes of poly-victimization among children in early adolescence, investigate transition probabilities between these latent categories, and examine the influencing factors. Methods: We used stratified cluster random sampling to select 2275 junior high students from five rural middle schools in Shantou and Jieyang, China, and surveyed them in two waves. Latent Class Analysis (LCA) and Latent Transition Analysis (LTA) identified latent classes of poly-victimization, and multi-factor logistic regression examined factors influencing the probability of students transitioning between these latent classes. Results: LCA identified three categories of poly-victimization: low poly-victimization, group, and high child maltreatment and peer and sibling victimization. The probabilities of remaining in the high child maltreatment and peer and sibling victimization group, transitioning to the transition group, or shifting to the low poly-victimization group were 37.00%, 29.20%, and 33.80%, respectively. Most transition group members remained in the same group, with a conversion probability of 77.10%, followed by transitioning to the low poly-victimization group with a probability of 15.80%. Physically healthy children, compared to those with disabilities or illnesses, were less likely to switch from the low poly-victimization group to the transition group (OR=0.034) or the high child maltreatment and peer and sibling victimization group (OR=0.14). Non-left-behind children, compared to left-behind children, have a higher probability of switching from the high child maltreatment and peer and sibling victimization group to the low poly-victimization group (OR=6.905). Conclusion: The high child maltreatment and peer and sibling victimization group had similar probabilities of transitioning into other categories. Physical illness or disability, as well as being left behind, are significant risk factors for children transitioning from the low-harm group to the high-harm group. [ABSTRACT FROM AUTHOR]