Phosphorus-
and silicon-modified graphene oxide was prepared to
improve the thermal stability and flame retardancy properties of epoxy
resin. 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and
vinyltriethoxysilane (VTES) were successfully grafted onto the surface
of graphene oxide (GO) through solvothermal synthesis and hydrolysis–condensation
reaction, respectively. Subsequently, the functionalized graphene
oxide grafted by DOPO and VTES (DOPO–VTES–GO) was incorporated
into the epoxy resin by the solution blending method. The effect of
DOPO–VTES–GO on the thermal stability and flame-retardant
properties of epoxy resin was systematically studied. Thermogravimetric
analysis showed that the thermal stability and char residue yield
of DOPO–VTES–GO/epoxy were increased obviously compared
with those of pure epoxy resin and DOPO–GO/epoxy. Cone calorimeter
test results showed that DOPO–VTES–GO/epoxy had better
flame retardancy than pure epoxy resin and DOPO–GO/epoxy on
reducing the peak of heat release rate, total heat release, and total
smoke production. Furthermore, the char residue after the cone calorimeter
tests was investigated by scanning electron microscopy–energy-dispersive
X-ray spectrometry, Raman spectroscopy, and Fourier transform infrared
measurements. These results demonstrated that the DOPO–VTES–GO
can enhance the graphitization degree of char residues and promote
the formation of the thermally stable char. In addition, the mechanism
of flame retardancy was proposed, and DOPO–VTES–GO exerts
the synergistic effect mainly by means of catalytic charring in the
condensed phase and capturing hydroxyl or hydrogen radicals from thermal
decomposition of epoxy resin in the gas phase. This work provides
novel insights into the preparation of phosphorus–silicon–graphene
oxide ternary synergistic flame retardants for thermosetting polymer
materials.
Sartorius muscle-pedicle bone graft significantly promotes repair of osteonecrosis of the femoral head, improves the Harris score of the hip joints, with good clinical efficacy. It effectively improves the survival rate of femoral head, delaying or preventing artificial hip replacement.
The minimally invasive treatment of ONFH with ABR showed promising results in delaying or even terminating the progression of the necrosis and improving hip function, especially in younger patients and in the early stages of the disease.
Presently, biomechanical support therapy for the femoral head has become an important approach in the treatment of early osteonecrosis of the femoral head (ONFH). Previous studies have reported that the titanium metal trabecular bone reconstruction systems (TMTBRS) achieved satisfactory clinical results for the treatment of early femoral head necrosis. Electron beam melting technology (EBMT) is an important branch of 3D printing technology, which enables the construction of an interface that is required for support of bone in-growth. However, the effect of TMTBRS created using EBMT for clinical applications for early ONFH is still unknown. At present, there are no reports on this topic worldwide. The purpose of this study was to assess the safety of a new 3D printed TMTBRS implant and to evaluate its clinical efficacy in early ONFH.Thirty patients who underwent surgery for ONFH were selected. The stages of ONFH were classified according to the Association Research Circulation Osseus (ARCO) classification. They were followed-up and radiological examination was performed at 6, 12, and 24 months post-surgery to assess TMTBRS stability and bone growth in the bone trabecular holder portion surface. To evaluate hip function, postoperative Harris and Visual Analogue Scale (VAS) scores were used.The postoperative Harris score increased significantly and VAS score decreased significantly at the 12-month follow-up compared to the 24-month follow-up, wherein the Harris score declined slightly and the VAS score was slightly elevated with the aggravation of ONFH. With the passage of time, postoperative improvement rates were 100% for IIA, 70% for IIB, and 0% for IIC. Hip-preserving rates were 100% for IIA, 100% for IIB, and 50% for IIC.The effect of TMTBRS treatment for early ONFH in ARCO IIA and ARCO IIB is satisfactory. However, it is not recommended for a relatively large area of necrosis such as in ARCO IIC.
AWPPH is a newly discovered long noncoding (lnc)RNA that plays an oncogenic role in development of several types of malignancies, whiles its involvement in non-traumatic osteonecrosis of femoral head (ONFH) is unknown. Therefore, the present study aimed to investigate the functionality of AWPPH in non-traumatic ONFH. Blood and mesenchymal stem cells (MSCs) were obtained from both non-traumatic ONFH patients and healthy controls, and expression of AWPPH in those tissues was detected by RT-qPCR. Receiver operating characteristic curve analysis was performed to investigate the diagnostic value of lncRNA AWPPH expression for non-traumatic ONFH. Bone morphogenic protein (BMP-2) was used to treat MSCs to induce osteogenic differentiation and the effects on lncRNA AWPPH expression was detected by RT-qPCR. LncRNA AWPPH overexpression and short hairpin (sh)RNA silencing cell lines were established and the effects on runt-related transcription factor 2 (Runx2) expression were detected by western blotting. It was demonstrated that AWPPH was significantly downregulated in non-traumatic ONFH patients compared with in healthy controls in both MSCs and serum. Expression of AWPPH in MSCs and serum is a sensitive diagnostic marker for non-traumatic ONFH. Expression of AWPPH exhibited no significant correlation with patients' age, gender and living habits, but was significantly correlated with course of disease. BMP-2 treatment significantly increased the expression level of AWPPH in human MSCs from bone marrow (hMSC-BM). AWPPH overexpression promoted, while AWPPH short hairpin RNA silencing inhibited the expression of Runx2 expression in hMSC-BM cells. Therefore, it was concluded that lncRNA AWPPH may participate in the development of ONFH by upregulating Runx2.
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