The paper presents the construction of a multi-dipole model that allows reproducing magnetic signatures of ferromagnetic objects. The virtual object used in the paper is an ellipsoid, which is the source of synthetic data. To make the situation more realistic, noise is added to the synthetic data. Two significant improvements compared to previous work are presented. Three-axial magnetometers are introduced instead of uniaxial magnetometers. However, a more important change is the modification of the model structure that allows placing dipoles on the entire plane, e.g. object’s deck. The multi-dipole model consists of an a priori assumed number of permanent and induced single-dipole models. Each single dipole is described by three magnetic moments and, depending on the applied approach, one or two dipole position parameters. The non-linear least-squares optimization method is used to determine model parameters. To assess the quality of magnetic signature reproduction, qualitative and quantitative forms are used. The final quality assessment is based on differences between the reference fields and the fields determined from the multi-dipole model. The applied modifications bring significant improvement, however, only their combined application allows to restore magnetic signatures with good quality for directions other than for which the data were available.

The article presents a continuation of the research on the 3D multi-dipole model applied to the reproduction of magnetic signatures of ferromagnetic objects. The model structure has been modified to improve its flexibility - model parameters determined by optimization can now be located in the cuboid contour representing the object’s hull. To stiffen the model, the training dataset was expanded to data collected from all four cardinal directions. The robustness of the modified multi-dipole model was verified with various noise levels applied to the synthetic data. A comprehensive numerical verification of the proposed methodology was performed using only data not involved in determining the modified multi-dipole model parameters: the data from intercardinal directions and from different depth were used for cross-validation. An analysis of the influence of initial conditions on the optimization process was carried out. In addition to the gradient optimization method, an evolutionary strategy was also used. Regularization was carried out to search for effective model parameterization. New verification methods were also applied based on the balance of magnetic moments and on the average width of the fit error interval. The results of the performed experiments have shown high robustness of the modified multi-dipole model, even in the face of high noise in the input data. The most significant advantage of the model is its predictive ability, enabling determination of magnetic signatures in any directions and depths with high accuracy.

Aims: In recent years, survival in patients with breast cancer has increased. Despite the improvement in outcomes of those patients, the risk of treatment-related cardiotoxicity remains high, and its presence has been associated with a higher risk of treatment termination and thus lower therapeutic efficacy. Prior trials demonstrated that a preventive initiation of heart failure drugs, including the renin–angiotensin–aldosterone inhibitors, might reduce the risk of treatment-related cardiotoxicity. However, to date, no study investigated the efficacy of sacubitril/valsartan, a novel antineurohormonal drug shown to be superior to the previous therapies, in the prevention of cardiotoxicity in patients with early-stage breast cancer, which is the aim of the trial. Methods and results: MAINSTREAM is a randomized, placebo-controlled, double-blind, multicentre, clinical trial. After the run-in period, a total of 480 patients with early breast cancer undergoing treatment with anthracyclines and/or anti-human epidermal growth factor receptor 2 drugs will be randomized to the highest tolerated dose of sacubitril/valsartan, being preferably 97/103 mg twice daily or placebo in 1:1 ratio. The patients will be monitored, including routine transthoracic echocardiography (TTE) and laboratory biomarker monitoring, for 24 months. The primary endpoint of the trial will be the occurrence of a decrease in left ventricular ejection fraction by ≥5% in TTE within 24 months. The key secondary endpoints will be the composite endpoint of death from any cause or hospitalization for heart failure, as well as other imaging, laboratory, and clinical outcomes, including the occurrence of the cancer therapy-related cardiac dysfunction resulting in the necessity to initiate treatment. The first patients are expected to be recruited in the coming months, and the estimated completion of the study and publication of the results are expected in December 2027, pending recruitment. Conclusions: The MAINSTREAM trial will determine the efficacy and safety of treatment with sacubitril/valsartan as a prevention of cardiotoxicity in patients with early breast cancer (ClinicalTrials.gov number: NCT05465031).

The paper presents a new analytical four-layer (air–water–bottom–non-conductive layer) horizontal electric dipole model which allows an accurate approximation of ship's Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of static electric components of UEP around the ship. These methods enable analyses with high accuracy but, compared to other point-electrode methods and the proposed analytical model, they are relatively complex and need high computational time. The developed analytical model proposed in this paper allows real-time calculations without significant loss of accuracy of the UEP estimations. In the model, the problem of boundary values at the borders of individual layers is solved using the reflection/image method and applying the idea of continuity of electric potential at a given boundary between two adjacent layers. Its accuracy is verified based on the synthetic data provided by specialised software packages making use of FEM and BEM numerical methods. A dimensionless quantitative analysis of the relationships between basic parameters of the proposed four-layer analytical model and their impact on the accuracy of representation of individual electric field strength components is also delivered. The relationships between water and bottom conductivity and between water depth and bottom thickness are investigated and described. The obtained results show that the developed model allows detailed and reliable analysis of the electric field, especially in shallow coastal waters.