ABSTRACT
This paper proposes a concept of soil shear strength exertion around an anchorage section to analyze and calculate the anchor's force and displacement. First, based on the Mohr stress circle, the numerical relationship between the value of the internal friction angle exertion, the value of the cohesion exertion, and the displacement are established under the non-limit active state. According to the interaction mechanism between the anchorage section and the surrounding soil, this paper obtains the corresponding relationship between the value of the soil's shear strength exertion and displacement under the non-limit active state. Then, according to the load transfer principle of the anchorage section, the basic differential equation is established. The differential equation of the relative displacement distribution along the length of the anchorage section under the non-limit active state is further derived. And the calculation and analysis formula of the shear stress and relative displacement in the anchorage section considering the process of the soil shear strength exertion is also obtained. Finally, this paper compares the calculation method with the hyperbolic model calculation method for the same example. The results verify the accuracy of the calculation method.
ABSTRACT
Objective This study was performed to examine serum microRNA-375 (miR-375) expression in patients with osteosarcoma and determine its diagnostic and prognostic value. Methods Serum samples were obtained from 95 patients with osteosarcoma and 95 healthy individuals. miR-375 expression was detected by real-time polymerase chain reaction. The associations of serum miR-375 expression with the patients' clinicopathological characteristics and prognosis were then evaluated. Receiver operating characteristic curve analysis was performed to obtain the potential value of serum miR-375 as a biomarker for osteosarcoma diagnosis and chemosensitivity prediction. Results Serum miR-375 expression was significantly lower in patients with osteosarcoma than in healthy individuals. Low serum miR-375 levels were associated with advanced clinical stages, large tumor size, positive distant metastasis, and poor tumor response to preoperative chemotherapy. Receiver operating characteristic curve analysis illustrated that serum miR-375 could distinguish patients with osteosarcoma from healthy individuals and distinguish patients with a good pathologic response from those with a poor response. Multivariate analysis confirmed low serum miR-375 expression as a statistically significant independent unfavorable prognostic factor. Conclusions Serum miR-375 expression was downregulated in patients with osteosarcoma and might serve as a biomarker for its diagnosis, prognosis, and chemosensitivity prediction.
Subject(s)
Biomarkers, Tumor/genetics , Bone Neoplasms/diagnosis , MicroRNAs/genetics , Osteosarcoma/diagnosis , Adolescent , Adult , Biomarkers, Tumor/blood , Bone Neoplasms/drug therapy , Bone Neoplasms/genetics , Bone Neoplasms/mortality , Case-Control Studies , Child , Doxorubicin/therapeutic use , Female , Humans , Male , Methotrexate/therapeutic use , MicroRNAs/blood , Neoadjuvant Therapy/methods , Neoplasm Staging , Osteosarcoma/drug therapy , Osteosarcoma/genetics , Osteosarcoma/mortality , Prognosis , ROC Curve , Survival Analysis , Treatment Outcome , Tumor Burden/drug effectsABSTRACT
The repair of various segmental tibial bone defects continues to be a challenging part of many reconstructive procedures. Many methods have been tried to repair the defects, followed by many complications and the results may be unsatisfied. Since 2001 Zuk et al. established human adipose-derived stem cells (hASCs) as a multipotent stem cell population with the ability to assume osteogenic phenotypes through chemically induced differentiation, hASCs represent a valuable tool for pharmacological and biological studies of osteoblast differentiation in vitro and bone development in vivo, and have been proved to be a useful source of stem cells in bone repair. Recently, hASCs have been found to repair both animals and human calvarial defects. In this paper, we hypothesize that hASCs cultured on custom scaffolds can be used to repair of tibial segmental bone defects with intramedullary nail internal fixed. Unlike current treatment modalities, it would promote the regeneration of tibial defects, provide structural support and allow for weight bearing and bony substitution over time.
