Objective: For diagnosing osteosarcoma correctly, a combination of clinical, radiological and histological examinations is required. Erroneous treatment may cause local contamination and systemic seeding in patients. The purpose of this study was to compare outcomes of planned and unplanned treatment for osteosarcoma. Methods: A retrospective review of patients with high-grade osteosarcoma who received appropriate surgical treatment and chemotherapy (n ¼ 134) and those who were misdiagnosed and received unplanned surgery (n ¼ 16) between July 1995 and February 2005. Results: Patients who received unplanned treatment were older (mean age: 29.7 vs. 19.7 years; P ¼ 0.003) and had a smaller mean tumor volume (119 vs. 280 ml; P ¼ 0.015). The 5-year survival rate was not statistically different between the groups. Patients who had unplanned treatment had a higher local recurrence rate (43.8 vs. 17.9%; P ¼ 0.024) and a shorter mean time for recurrence (11.9 vs. 20.8 months; P ¼ 0.036). Furthermore, in patients who underwent unplanned treatment, lung metastases occurred earlier (6.1 vs. 16.2 months P ¼ 0.021) and the final limb salvage rate was less (68.7 vs. 87.3%; P , 0.001). Conclusions: Unplanned treatment for high-grade osteosarcoma can result in failure of local control and earlier systemic metastases.
Alternating current field Measurement is one of the important progresses about electromagnetic nondestructive testing in recent years. Alternating magnetic fields excitation testing model is established by using electromagnetic simulation software ANSOFT, a flat plate crack defects are simulated. By analyzing its principle, crack depth and the width change influence on test results, finally the simulation results are verified by the method of experiment. The experimental results are consistent with the simulation results. The results show that this differential probe has good effect on crack defects test.
Metal Magnetic Memory (MMM) testing method has its own effective and unique advantages on the research of extension of metal crack. The array magnetic memory testing sensor designed and assembled in accordance with specific conditions, could evidently enhance testing-efficiency, such as for components with complex shape or large surface area, and may simplify the test equipment correspondingly. A kind of array magnetic memory sensor with Hall elements as core components was designed and an experiment on metal magnetic memory testing on extension of metal crack was executed. The experiment results indicate that the magnetic memory testing technique could effectively monitor and qualitatively evaluate the progress of metal crack extension.
The relations between stresses and leakage magnetic signal of concentration area of the airplane’s landing gear under varying load were studied. The finite element method was used to calculate the stress of axle under different conditions; An experiment was designed to simulate the stress status under the bending moment, the slight magnetic signals on specimen were measured, and the relation of the signals and stress was studied. The new testing method was explained with the theory of ferromagnetic and the significance of this technique for detecting defects of the airplane structural part was discussed. The safety of airplane’s main bearing parts plays an important role during its operation and it often comes to bad situation of fatigue damage for stress concentration [1, 2]. To prevent the breaking down of structural parts and get rid of big accidents, it becomes important and necessary to find out the early concentration and damage zone, and to make some certain examination of damage and stress status [3]. The method of magnetic memory testing would be effective for the confirming of stress concentration zone in the equipment or structural parts, and could lead the way ahead the matters of fatigue analysis, evaluation of equipment life and technological design. The method can detect the endurance failure of the airplane’s undercarriage shaft, which is composed of ferromagnetic materials, and that provides the experimental basis for the prevention of parts’ fatigue defects.
Crack propagation is the main reason which leads to the invalidity of the metal components. A set of detecting equipment based on the acoustic emission method was designed, and it was mainly composed of acoustic emission sensor, signal operating circuits and signal acquisition system. Specimens of 16MnR material were manufactured and the static axial tension test of them was carried on. Acoustic emission signals from the specimen were detected by acoustic emission equipment by using piezoelectric ceramic sensor. Signal datum were acquired and operated by the acquisition system, as well as the acquisition program written for it. The final results has demonstrated that acoustic emission equipment designed for the test performed well in acquiring the signals induced by the metal crack propagation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.