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1.
J Orthop Translat ; 43: 21-35, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37965195

RESUMO

Background: Large defects of long tubular bones due to severe trauma, bone tumor resection, or osteomyelitis debridement are challenging in orthopedics. Bone non-union and other complications often lead to serious consequences. At present, autologous bone graft is still the gold standard for the treatment of large bone defects. However, autologous bone graft sources are limited. Silicon rubber (SR) materials are widely used in biomedical fields, due to their safety and biocompatibility, and even shown to induce nerve regeneration. Materials and methods: We extracted rat bone marrow mesenchymal stem cells (BMMSCs) in vitro and verified the biocompatibility of silicone rubber through cell experiments. Then we designed a rabbit radius critical sized bone defect model to verify the effect of silicone rubber sealed channel inducing bone repair in vivo. Results: SR sealed channel could prevent the fibrous tissue from entering the fracture end and forming bone nonunion, thereby inducing self-healing of long tubular bone through endochondral osteogenesis. The hematoma tissue formed in the early stage was rich in osteogenesis and angiogenesis related proteins, and gradually turned into vascularization and endochondral osteogenesis, and finally realized bone regeneration. Conclusions: In summary, our study proved that SR sealed channel could prevent the fibrous tissue from entering the fracture end and induce self-healing of long tubular bone through endochondral osteogenesis. In this process, the sealed environment provided by the SR channel was key, and this might indicate that the limit of self-healing of bone exceeded the previously thought. The translational potential of this article: This study investigated a new concept to induce the self-healing of large bone defects. It could avoid trauma caused by autologous bone extraction and possible rejection reactions caused by bone graft materials. Further research based on this study, including the innovation of induction materials, might invent a new type of bone inducing production, which could bring convenience to patients. We believed that this study had significant meaning for the treatment of large bone defects in clinical practice.

2.
Adv Mater ; 32(40): e2003790, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32881186

RESUMO

Perovskite X-ray detectors have been demonstrated to be sensitive to soft X-rays (<80 keV) for potential medical imaging applications. However, developing X-ray detectors that are stable and sensitive to hard X-rays (80 to 120 keV) for practical medical imaging is highly desired. Here, a sensitive 2D fluorophenethylammonium lead iodide ((F-PEA)2 PbI4 ) perovskite single-crystal hard-X-ray detector from low-cost solution processes is reported. Dipole interaction of organic ions promotes the ordering of benzene rings as well as the supramolecular electrostatic interaction between electron-deficient F atoms with neighbor benzene rings. Supramolecular interactions serve as a supramolecular anchor to stabilize and tune the electronic properties of single crystals. The 2D (F-PEA)2 PbI4 perovskite single crystal exhibits an intrinsic property with record bulk resistivity of 1.36 × 1012 Ω cm, which brings a low device noise for hard X-ray detection. Meanwhile, the ion-migration phenomenon is effectively suppressed, even under the large applied bias of 200 V, by blocking the ion migration paths after anchoring. Consequently, the (F-PEA)2 PbI4 single crystal detector yields a sensitivity of 3402 µC Gy-1 air cm-2 to 120 keVp hard X-rays with lowest detectable X-ray dose rate of 23 nGyair s-1 , outperforming the dominating CsI scintillator of commercial digital radiography systems by acquiring clear X-ray images under much lower dose rate. In addition, the detector shows high operation stability under extremely high-flux X-ray irradiation.

3.
Front Neurosci ; 13: 679, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354406

RESUMO

Objectives: To evaluate white matter hyperintensities (WMH) quantification reproducibility from multiple aspects of view and examine the effects of scan-rescan procedure, types of scanner, imaging protocols, scanner software upgrade, and automatic segmentation tools on WMH quantification results using magnetic resonance imaging (MRI). Methods: Six post-stroke subjects (4 males; mean age = 62.8, range = 58-72 years) were scanned and rescanned with both 3D T1-weighted, 2D and 3D T2-weighted fluid-attenuated inversion recovery (T2-FLAIR) MRI across four different MRI scanners within 12 h. Two automated WMH segmentation and quantification tools were used to measure WMH volume based on each MR scan. Robustness was assessed using the coefficient of variation (CV), Dice similarity coefficient (DSC), and intra-class correlation (ICC). Results: Experimental results show that the best reproducibility was achieved by using 3D T2-FLAIR MRI under intra-scanner setting with CV ranging from 2.69 to 2.97%, while the largest variability resulted from comparing WMH volumes measured based on 2D T2-FLAIR MRI with those of 3D T2-FLAIR MRI, with CV values in the range of 15.62%-29.33%. The WMH quantification variability based on 2D MRIs is larger than 3D MRIs due to their large slice thickness. The DSC of WMH segmentation labels between intra-scanner MRIs ranges from 0.63 to 0.77, while that for inter-scanner MRIs is in the range of 0.63-0.65. In addition to image acquisition, the choice of automatic WMH segmentation tool also has a large impact on WMH quantification. Conclusion: WMH reproducibility is one of the primary issues to be considered in multicenter and longitudinal studies. The study provides solid guidance in assisting multicenter and longitudinal study design to achieve meaningful results with enough power.

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