Comparison of MRI radiomics-based machine learning survival models in predicting prognosis of glioblastoma multiforme

ObjectiveTo compare the performance of radiomics-based machine learning survival models in predicting the prognosis of glioblastoma multiforme (GBM) patients.Methods131 GBM patients were included in our study. The traditional Cox proportional-hazards (CoxPH) model and four machine learning models (SurvivalTree, Random survival forest (RSF), DeepSurv, DeepHit) were constructed, and the performance of the five models was evaluated using the C-index.ResultsAfter the screening, 1792 radiomics features were obtained. Seven radiomics features with the strongest relationship with prognosis were obtained following the application of the least absolute shrinkage and selection operator (LASSO) regression. The CoxPH model demonstrated that age (HR = 1.576, p = 0.037), Karnofsky performance status (KPS) score (HR = 1.890, p = 0.006), radiomics risk score (HR = 3.497, p = 0.001), and radiomics risk level (HR = 1.572, p = 0.043) were associated with poorer prognosis. The DeepSurv model performed the best among the five models, obtaining C-index of 0.882 and 0.732 for the training and test set, respectively. The performances of the other four models were lower: CoxPH (0.663 training set / 0.635 test set), SurvivalTree (0.702/0.655), RSF (0.735/0.667), DeepHit (0.608/0.560).ConclusionThis study confirmed the superior performance of deep learning algorithms based on radiomics relative to the traditional method in predicting the overall survival of GBM patients; specifically, the DeepSurv model showed the best predictive ability

Evaluation of Mine Water Quality Based on Bayesian Theory MODEL of AHP-EWM Combined Weighting Method

In view of the fuzziness and randomness of groundwater quality evaluation and the rationality and scientificityof the weight in the evaluation process, in order to establish an objective, scientific and convenient mine waterenvironment evaluation system and improve the accuracy of the evaluation results, AHP and EWM weight method arecombined to obtain the weight value, which is coupled with Bayesian water quality evaluation model. In this paper, sevenwater quality evaluation factors and ten groups of water samples are selected to analyze the application of mine water inShengquan coal mine, Shandong Province. At the same time, the single factor evaluation method, equal weightBayesian model and fuzzy comprehensive evaluation method are used to compare with the evaluation results to verifythe accuracy of the evaluation results of the model. The results show that the water quality evaluation model ofcombined weighted Bayesian model is reasonable for mine water quality evaluation, which not only distinguishes thedifference of each evaluation factor's contribution to water quality, but also makes a more accurate evaluation of waterquality, and the calculation process is simple, which avoids the complexity of multiple indicators of traditional methods,and provides a scientific basis for comprehensive utilization of mine water in mining area, so the evaluation method ispractical. &nbsp

How to prevent landscape ecological risk with a land use optimal allocation system: An empirical study of the Yellow River Delta in China

Irrational land use is a key factor in triggering regional landscape ecological risk (LER). Existing studies have focused on the relationship between land use change and LER, but it is still unclear how to prevent the risk through the land use optimal allocation (LUOA). To fill these gaps, this study innovatively designs a research framework that follows the logic of “risk assessment – suitability assessment – potential identification – optimal allocation – risk avoidance”. Using methods such as LER index, land use suitability (LUS) evaluation model and spatial overlay analysis, this study investigates the path and feasibility of LER prevention from the perspective of LUOA. The Yellow River Delta (YRD) with frequent interactions between society and ecosystem is taken as a case study. The results are as follows: (1) There was an inverse relationship between LER and comprehensive LUS in the YRD. In inland areas of the YRD, LER was relatively stable, while the comprehensive LUS was characterized by multi-suitability. In the coastal areas of the YRD, the level of LER was generally high, while the comprehensive LUS was characterized by single suitability and unsuitability; (2) The land use comprehensive development potential (LUCDP) was significant in the YRD, with a spatial distribution trend that increased from the coastal to the inland areas. This pattern reflects different orientations of the positive interaction between nature and society and land use support areas; and (3) After conducting LUOA, cultivated land, forest land, and grassland increased by 395 km2, 196 km2, and 174 km2, respectively. The wetlands, construction land, and unused land increased by 32 km2, 248 km2, and 319 km2, respectively. After recalculation, the above scheme can prevent the regional LER. In summary, the present study offered a new approach for achieving a mutually beneficial outcome between landscape ecological risk management and land use optimization, which is significant for the ecological management of river estuary areas in China and in the world

Microstructure analysis of 7050 aluminum alloy joint fabricated by linear friction weld

The microstructure of a linear friction welded joint of 7050 aluminum alloy was investigated through optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The analysis focused on grain boundary types, microstructure, and mechanical properties of the joint. The results reveal that fine equiaxed crystals are generated in the welded zone through dynamic recrystallization. The average grain size is 6.8 μm, with a volume fraction of large angle grain boundaries reaching 69.5%. The microstructure primarily consists of Cube {001} texture, {111} Brass recrystallization texture, and a small amount of copper {112} deformation texture. The thermo-mechanically affected zone (TMAZ) presents a linear structure with an average grain size of 15.8 μm and a volume fraction of 36.1% at large grain boundary, resulting in a deformed Brass {011} texture and a small amount of {236} as well as {111} Brass recrystallization texture. The welded joint exhibits a tensile strength of 492 MPa and a yield strength of 380 MPa, which represents 94.2% and 78.5% of the base material, respectively. Furthermore, the elongation of the joint is 10.2% and 98% of the base material, respectively. The fracture of the tensile sample is observed in the TMAZ, showing good mechanical properties with a mixed fracture mode with some degrees of ductility and brittleness

Routing for Hazardous Materials Transportation in Urban Areas

Hazardous materials (HAZMAT) are important for daily production in cities, which usually have a high population. To avoid the threat to public safety and security, the routes for HAZMAT transportation should be planned legitimately by mitigating the maximum risk to population centers. For the objective of min-max local risk in urban areas, this study has newly proposed an optimization model where the service of a link for HAZMAT transportation was taken as the key decision variable. Correspondingly, the symmetric problem of min-max optimization takes significant meanings. Moreover, in consideration of the work load of solving the model under a lot of decision variables, a heuristic algorithm was developed to obtain an optimal solution. Thereafter, a case study was made to test the proposed model and algorithm, and the results were compared with those generated by deterministic solving approaches. In addition, this research is able to be an effective reference for authorities on the management of HAZMAT transportation in urban areas

Pulmonary Artery Dissection: A Fatal Complication of Pulmonary Hypertension

Pulmonary artery dissection is extremely rare but it is a really life-threatening condition when it happens. Most patients die suddenly from major bleeding or tamponade caused by direct rupture into mediastinum or retrograde into the pericardial sac. What we are reporting is a rare case of a 46-year-old female patient whose pulmonary artery dissection involves both the pulmonary valve and right pulmonary artery. The patient had acute chest pain and severe dyspnea, and the diagnosis of pulmonary artery dissection was confirmed by ultrasonography and CT angiography. Moreover, its etiology, clinical manifestations, and management are also discussed in this article

Effect of Yb2O3 on superplastic behavior of laser welded joint of TC4 titanium alloy

The inhomogeneity of joints during superplastic deformation greatly limits the application of laser beam welding/superplastic forming (LBW/SPF). In order to adjust the deformation uniformity of the joint, Yb2O3 with different mass fractions was added to the laser welded joint of TC4 titanium alloy, and the effect of Yb2O3 on the superplastic deformation behavior of the laser welded joint of TC4 titanium alloy was studied. The results showed that the addition of Yb2O3 can effectively refine β grains. At Yb2O3 content of 6 wt%, the refinement effect of Yb2O3 on the weld grains is the most obvious. At this time, the peak flow stress of the longitudinal weld sample reaches a minimum value of 25.6 MPa, and the superplasticity of the joint is significantly improved. The elongation of the transverse welded sample reached 29% of that of the base metal and the joint deformation uniformity was significantly improved. The prior β grain of weld broke during superplastic deformation, and the acicular martensite structure in the weld was gradually transformed into a lamellar structure. After the addition of Yb2O3, the lamellar structure inside the weld becomes short and disordered, which promotes occurrence of superplastic deformation