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Objectives Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. Lung metastasis (LM) occurs in more than half of patients at different stages of the disease course, which is one of the important factors affecting the long-term survival of OS. To develop and validate machine learning radiomics model based on radiographic and clinical features that could predict LM in OS within 3 years. Methods 486 patients (LM = 200, non-LM = 286) with histologically proven OS were retrospectively analyzed and divided into a training set (n = 389) and a validation set (n = 97). Radiographic features and risk factors (sex, age, tumor location, etc.) associated with LM of patients were evaluated. We built eight clinical-radiomics models (k-nearest neighbor [KNN], logistic regression [LR], support vector machine [SVM], random forest [RF], Decision Tree [DT], Gradient Boosting Decision Tree [GBDT], AdaBoost, and extreme gradient boosting [XGBoost]) and compared their performance. The area under the receiver operating characteristic curve (AUC) and accuracy (ACC) were used to evaluate different models. Results The radscore, ALP, and tumor size had significant differences between the LM and non-LM groups (tradscore = -5.829, χ2ALP = 97.137, tsize = -3.437, P P Conclusion The clinical-radiomics model had good performance in predicting LM in OS, which would be helpful in clinical decision-making.

To address the tracking control problem for n-DOF parallel robots in presence of the lumped disturbance, including modeling errors, friction and external disturbance, a finite-time stable robust sliding mode dynamic control (FRSMDC) for parallel robots is explored. From the implementation condition of the FRSMDC for parallel robots, the limitation on the change rate of the lumped disturbance is relaxed for easy realization. From the results of the FRSMDC for parallel robots, the finite-time stability of the sliding variable is proved and the settling time is derived; the switching gain required is only larger than the upper bound of the disturbance estimation error, instead of the upper bound of the disturbance, due to the feed-forward compensation to the lumped disturbance via a disturbance observer. Consequently, the system robustness is improved and the chattering of FRSMDC is alleviated. The finite-time stability of the closed-loop system is confirmed with Lyapunov theory. Besides, the application of the proposed method is extended to a general multi-input multi-output nonlinear system with the relative degree m by analogy. Finally, the case of the dynamic control of a 6-DOF parallel robot for automobile electro-coating conveying is studied for simulation and experiment, so as to attest the validity of the FRSMDC for parallel robots.

An electret-based mechanical antenna (EBMA), which can transmit extremely low frequency (ELF) electromagnetic signals, has the advantages of miniaturization and high transmitting efficiency, with great potential applications in air, underwater, and underground communications. To improve the charge density of the electret, which is a key factor in determining the radiation performance of an EBMA, this work proposes a fluorinated ethylene propylene/terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (FEP/THV) unipolar electret exhibiting negative polarity, reaching a total charge density up to −0.46 mC/m2 for each layer of electret. Long transmission distances can be achieved in sea water, soil, and air using a 3-layer-FEP/THV-based EBMA with a compact volume of 5 × 10−4 m3. As an application demonstration, binary ASCII-coded ELF information of “BUAA” is successfully transmitted with a power consumption

Although organic semiconductors with high mobility and thermal stability are particularly desirable for practical applications, facile methods for their development still remains a big challenge. In this work, a charge-transfer cocrystal based on fullerene (C70)/cobalt porphyrin supramolecular architecture was prepared by a solution-processable co-assembly strategy. This supramolecular architecture showed hole mobility as high as 4.21 cm2·V−1·s−1, and a relatively high mobility of 0.02 cm2·V−1·s−1 even after thermal treatment at 1,000 °C. Further studies confirmed the occurrence of charge-transfer from 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinato cobalt(II) (CoTMPP) to C70 and the paramagnetic character within the supramolecular system. These factors were found to be responsible for the aforementioned superior performances. Thus, a novel organic semiconductor has been reported in this work, which can be potentially used for next generation electronic devices. Furthermore, it has been demonstrated that charge-transfer co-crystallization is a powerful strategy for the rational design and construction of a broad class of new multifunctional organic co-crystalline materials.