Follow-up study on gastric cancer treated with mitomycin C prior to surgical operation

With the purpose to prevent the dissemination and consequent metastasis of cancer cells at the time of operation we gave 10 mg of Mitomycin C per day for four consecutive days prior to surgical operation of gastric cancer (total of 322 patients), and this so-called adjuvant chemotherapy proved to be effective on the cases with serosal involvement and infiltrating type of cancer, irrespective of histological types. It also gave five-year survival rate of 35 per cent. However, to lymph nodes already metastasized, the adjuvant chemotherapy proved to be not effective.</p

RF Performance of Layer-Structured Broadband Passive Millimeter-Wave Imaging System

Low profile and simple configuration are advantageous for RF module in passive millimeter-wave imaging system. High sensitivity over broad operation bandwidth is also necessary to detect right information from weak signal. We propose a broadband layer-structured module with low profile, simple structure, and ease of manufacture. This module is composed of a lens antenna and a detector module that consists of a detector circuit and a broadband microstrip-to-waveguide transition. The module forms a layer structure as a printed substrate with detector circuit is fixed between two metal plates with horn antennas and back-short waveguides. We developed a broadband passive millimeter-wave imaging module composed of a lens antenna and a detector module in this work. The gain and the antenna efficiency were measured, and the broadband operation was observed for the lens antenna. For the detector module, peak sensitivity was 8100 V/W. Furthermore, the detector module recognized a difference in the absorber’s temperature. The designs of the lens antenna and the detector module are presented and the RF performances of these components are reported. Finally, passive millimeter-wave imaging of a car, a human, and a metal plate in clothes is demonstrated in this paper

Best Feed Positions and Radiation Patterns of Typical Multibeam Dielectric Lens Antenna

Multibeam base station antennas are introduced for 5G and 6G mobile communication systems. Considering higher frequency bands such as millimeter waves for 5G and terahertz for 6G, dielectric lens antennas become promising candidates due to their simple antenna configuration and excellent multibeam radiation characteristics. Therefore, it is important to identify the best multibeam antenna from the existing typical lens antennas. In this article, a shaped lens and some conventional lenses are considered. For the conventional types, the hyperbolic-planar, plano-convex, and spherical-convex are selected. As for the shaped lens, Abbe&#x2019;s sine condition lens is selected. This research begins by finding the best feed position of four types of lenses. A MATLAB program is developed to find the smallest distance point for all focal region rays. Based on this point, the feed position is selected and multibeam radiation patterns of four lenses are obtained. It is shown that the spherical-convex lens can achieve the highest gain and the smallest beam shape degradation. High gain characteristics are obtained until a 35&#x00B0; beam shift. As for sidelobe characteristics, Abbe&#x2019;s sine condition lens has the lowest sidelobe level. These properties are then clarified using amplitude and phase distribution on the aperture plane. Furthermore, focal region ray concentration changes by $F/D$ and refractive index are discussed for practical applications

Broadband Waveguide-to-Differential-Line Transition in Multi-Layer Substrates With Triple Stacked Patch in 300 GHz Band

A broadband waveguide-to-differential-line transition with a triple stacked patch is proposed for use in 300 GHz band. This transition consists of differential signal lines inserted into the waveguide region from both broad walls of the waveguide. A triple circular stacked patch element was used for broadband transmission from the waveguide to the planar differential line formed in a multi-layer substrate. Concurrently, the optimized arrangement of via holes can prevent electric field leakage efficiently and improve the transmission characteristic in a high-frequency band. The geometry of the transition was optimized through electromagnetic simulations using the finite element method. Measurements and simulations were implemented to evaluate the performance of the transition. The measured result of the transition shows the bandwidth of the $S_{11}$ below &#x2212;10 dB was over 100 GHz