As a multifactorial disease, intervertebral disc degeneration (IVDD) causes many spinal-related diseases, which causes disability in the workforce and heavy social costs all over the world. Recently, Ganoderic Acid A (GAA) has been reported to play many pharmacological effects. However, its effect on IVDD remains unclear. In the present study, our study determined that GAA significantly inhibited H
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induced apoptosis, release of inflammatory cytokines and oxidative stress mediators in the nucleus pulposus (NP) cells. Moreover, GAA also suppressed H
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induced major matrix degrading proteases (MMP-3, MMP-13, ADAMTS4 and ADAMTS5) associated with NP degradation. Additionally, we found NP protective ability of GAA by up-regulating extra cellular matrix anabolic factors like type II collagen (Col II) and aggrecan in NP cells. Furthermore, we also demonstrated that GAA suppressed the activation of TLR4/NLRP3 in H
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-stimulated NP cells. Thus, our results demonstrate that GAA inhibited the H
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induced apoptosis, oxidative stress, and inflammatory responses through the depression of TLR4/NLRP3 signaling axis. GAA possess NP protective properties and may be of value in suppressing the pathogenesis of IVDD.
Objective
To develop a post‐traumatic osteoarthritic model of hip following fracture of acetabulum in rabbit for revealing biochemical mechanism of post‐traumatic osteoarthritis.
Methods
A total of 36 mature male New Zealand white rabbits were equally divided into sham group (n = 12), non‐ORIF group (n = 12), and open reduction and internal fixation (ORIF) group (n = 12). Except for the sham group, rabbits had survival surgeries to create acetabular fractures of dorsal wall for simulating dashboard impaction mechanism. The ORIF group received open reduction and internal fixation, while fractures in the non‐ORIF group were left as displaced but transverse fracture and dislocation was reduced. Besides intraoperative appearance and postoperative recovery, macroscopic and radiographic characteristics of the hips were recorded and assessed by a radiographic scoring scale at 3 weeks, 6 weeks, and 6 months, respectively.
Results
Out of 24 modeled acetabula, 21 (87.5%) were pure dorsal wall fractures as proposed and the remaining three were associated fractures (dorsal wall plus transverse fracture) accompanied by dorsal dislocation or not. All hips were stable, and no sciatic nerve injury was observed. One rabbit in the ORIF group died of deep infection 4 days after surgery. Rabbits in the sham and ORIF groups returned to normal gait in 2 weeks, but animals in the non‐ORIF group suffered from limping and restricted movement. As the time progressed, the hips in the non‐ORIF group experienced progressive and severe degeneration which exhibited dramatically malformed and hypertrophic joints at 6 months, but the ORIF group maintained much better morphological structure. Corresponding to morphological changes, the average radiographic scores of the non‐ORIF group increased from 1.25 at 3 weeks to 2.75 at 6 months and showed statistically significant difference when compared to the sham group at all three time points (P = 0.011, 0.011, 0.015, respectively, <0.0167). Although the scores of the ORIF group showed apparent improvements (increased from 0.67 at 3 weeks to 2.00 at 6 months), there was no significant difference between the two modeled groups at all three time points.
Conclusion
The fracture model with high consistency and reproducibility showed progressive post‐traumatic osteoarthritic changes which could be improved by open reduction and internal fixation surgery and provided an alternative selection for investigating potential pathogenesis and pathology of post‐traumatic osteoarthritis following fracture of acetabulum.
This paper describes some recent results on surface defects, uniformity, dislocation density as well as device applications of MBE growth of HgCdTe at the research center of advanced materials and devices. The features of different surface defects and their origins were studied by using SEMJEDX observations on HgCdTe epilayers with different growth conditions. A variety of surface defects was observed and the formation mechanism was discussed. A good uniformity was observed over 3-in HgCdTe wafers, the Stddev/mean in x and thickness were 1 .2%, and 2.7%, respectively. It was found that the dislocation density was sensitive to growth parameters and the composition. The ZnCdTe substrates with 4% mole fraction were found to be suitable for LW HgCdTe, however, for the HgCdTe of shorter wavelengths different Zn composition is required. An average value of EPD of 4.2x1 05cm2 was obtained for LW samples. The MBE grown HgCdTe were incorporated into some preliminary FPA devices.
The output feedback H∞ consensus control problem of multi‐agent systems is studied using an event‐triggered control strategy. Two types of transmission delays, one from the system output to the output feedback controller (OFC) and the other from the OFC to the zero‐order holder, are considered. This causes the OFC and the system not to be updated in the same time intervals. An interval dividing approach is applied to such that the whole system can be updated in the same time intervals. An event‐triggered OFC with H∞ performance is proposed for multi‐agent systems to achieve consensus. By constructing an appropriate Lyapunov–Krasovskii functional, sufficient conditions based on linear matrix inequality are derived to guarantee the consensus achievement. Finally, the theoretical results are validated using computer simulation.
Among the ways to construct experimental designs having been proposed, orthogonal design, uniform design, and D-efficient design are state-of-the-art methods. This article provides detailed comparisons on the efficiency and robustness among these methods with three case studies in multinomial logit and mixed multinomial logit models. ND-error values and the departures of D-errors corresponding to misspecification of prior information are used as measurements of design efficiency and design robustness, respectively. Design methods are described, and designs with various numbers of runs are constructed. The results indicate that (a) when parameter priors are available, D-efficient design method outperforms the other two methods, in terms of design efficiency, while uniform design and orthogonal design methods are comparable with each other; (b) there will be efficiency loss when D-efficient design that constructed for specific model is implemented in other ones; (c) all three methods have comparable robustness against misspecifications in parameter prior values; however, the effect of misspecification in prior distribution is massive when D-efficient design is used in mixed multinomial logit model; and (d) when parameter priors are unknown, uniform design is suggested to be used in the construction of experimental designs.
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