Far field in transient two-dimensional scattering

A heuristic definition of far field is given for time-domain two-dimensional scattering that simplifies the expression of the scattered far field as an integral over the sources. The meaning of this definition and of the ensuing simplifications is clarified by Fourier transforming the approximate time-domain result to compare it with well-known frequency-domain expressions in the Fresnel and Fraunhofer approximations.     

Dispersion relation for general anisotropic media

The dispersion relation is derived for an anisotropic medium with arbitrary tensor permittivity and permeability. Particular cases and applications to layered media are discussed.     

Immunotherapy as a Therapeutic Strategy for Gastrointestinal Cancer—Current Treatment Options and Future Perspectives

Gastrointestinal (GI) cancer constitutes a highly lethal entity among malignancies in the last decades and is still a major challenge for cancer therapeutic options. Despite the current combinational treatment strategies, including chemotherapy, surgery, radiotherapy, and targeted therapies, the survival rates remain notably low for patients with advanced disease. A better knowledge of the molecular mechanisms that influence tumor progression and the development of optimal therapeutic strategies for GI malignancies are urgently needed. Currently, the development and the assessment of the efficacy of immunotherapeutic agents in GI cancer are in the spotlight of several clinical trials. Thus, several new modalities and combinational treatments with other anti-neoplastic agents have been identified and evaluated for their efficiency in cancer management, including immune checkpoint inhibitors, adoptive cell transfer, chimeric antigen receptor (CAR)-T cell therapy, cancer vaccines, and/or combinations thereof. Understanding the interrelation among the tumor microenvironment, cancer progression, and immune resistance is pivotal for the optimal therapeutic management of all gastrointestinal solid tumors. This review will shed light on the recent advances and future directions of immunotherapy for malignant tumors of the GI system.     

Transient scattering by resistive cylinders

The two-dimensional scattering of an electromagnetic pulse normally incident on a collection of infinitely long cylinders of arbitrary shape is considered. ForE-polarization an electric field integral equation is derived that is applicable to solid cylinders and/or thin sheets, resistive and/or perfectly conducting. The contribution of the self-cell at later times is carefully analyzed. The expression obtained represents a generalization of previously known results. For an incident Gaussian pulse, numerical results are presented for surface currents and far-fields, for perfectly conducting and resistive circular cylinders and strips. A fast Fourier transform (FFT) algorithm is implemented to obtain the backscattering radar cross section, which is in good agreement with results obtained from either exact continuous wave (CW) solutions or the method of moments.     

A scheme for eliminating internal resonances: the parasitic bodytechnique

A scheme for solving ill-conditioned scattering problems associated with surface integral equations involving bodies of general composition is presented. It consists of analytically continuing a (parasitic) lossy body into the interior of a resonant geometry, where it interacts only with the resonance fields, attenuating them. The technique can be used to endow any surface code with internal resonant suppression capabilities provided it can handle, in addition to the scatterer, another lossy body or external R-sheets     

Two-dimensional scattering by a homogeneous anisotropic rod

An integral equation based on a plane wave representation of the fields in a simply connected and anisotropic medium has been derived in order to handle the problem of two-dimensional scattering by a homogeneous anisotropic cylinder. Its simplicity: one-dimensional, finite range of integration, one unknown with no derivatives of it involved, and a nonsingular kernel, results in an efficient and straightforward numerical implementation. Both polarizations are considered and computer results are presented, discussed, and used to check our scheme thoroughly.