407 research outputs found

    Influence of the cylindrical luneburg lens discretizayion on its antenna radiation properties

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    Исследуемая цилиндрическая линза Люнеберга представляет собой радиально неоднородную слоистую структуру. Исследуется влияние количества слоев дискретизации линзы на ее характеристики излучения. Рассмотрено четыре способа дискретизации линзы, для каждого из которых получены зависимости КНД от количества слоев, а также построены диаграммы направленности для варианта линзы из трех слоев и внешнего радиуса 3λ. Для расчета диаграмм направленности и КНД использовалась математическая модель, созданная на основе аппарата тензорных функций Грина стратифицированных сред в цилиндрической системе координат. Определен оптимальный способ выбора закона изменения толщины и диэлектрической проницаемости слоев.The cylindrical Luneburg lens under analysis has a radially unhomogeneous layered structure. The influence of the number of layers on lens antenna radiation properties is investigated. Four ways lenses discretization is considered. For each way antenna directivity is analyzed. Radiation patterns of three-layer Luneburg lens and 3-wavelength outer radius are shown. To calculate radiation patterns and antenna directivity a model based on Green’s functions of cylindrical layered structure was used. The optimal method of cylindrical Luneburg lens layer’s permittivity and thickness choice is suggested.Исследование выполнено за счет гранта Российского научного фонда (проект №14-19-01396)

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

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    Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

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    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

    Radiation Patterns of Patch Antennas on Coated Conducting Cylinders

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    The development of the Internet of Things and communication systems of the fifth generation leads to the need to place many antenna elements in a limited volume. Therefore, wearable electronics antennas are often located directly on the device body. Such surfaces can often be thought of as a conducting cylinder covered with a dielectric material. The task of analysing the radiation patterns of antennas located on such surfaces becomes urgent. This paper shows a method for analysing antenna directivity diagrams using the Green's functions method of cylindrical layered media. This method allows to obtain in an analytical form the expressions for the analysis of such structures, which makes it possible to reduce the cost of computer time in modelling. The presented results show what kind of distortions are introduced into the radiation pattern of antennas located on a cylinder compared to an antenna located on a flat surface. © 2021 Institute of Physics Publishing. All rights reserved.The research was executed by the Grant of the Ministry of science and higher education of the Russian Federation (Project N 0836–2020–0020)

    How the green's functions may be used for correcting measurements of transmission through flat homogeneous and sandwich-type dielectric sheets

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    The Green's functions of layered structures are used for analysis of measurement errors of transmitting losses through solid and sandwich-type dielectric structure. Influence of the spherical waves excited by radiators in the near zone is under investigation. As the simplest antenna, the Huygens element was used for calculations. The model of equivalent electric circuits was used for layered structure modelling. The transmitting losses of electromagnetic waves versus frequency for different dielectric sheets are shown. Influence of the distance between antennas on the transmitting losses measurements is analyzed. It is proposed to use the suggested method to analyze the accuracy of the transmission coefficients measurements if the horn antennas are used. © 2020 American Institute of Physics Inc.. All rights reserved.This work was supported by the Grant of the Ministry of Science and Higher Education of the Russian Federation (project no 8.2538.2017/4.6)

    Investigation of spherical and cylindrical Luneburg lens antennas by Green's function method

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    Luneburg lens antenna radiation fields are calculated with Green's functions of spherical and cylindrical layered structures. Electric field components for Luneburg lenses excited by a linear and circular polarized antenna are analyzed. Co-polarized and cross-polarized field radiation patterns are shown. Reflection from the lens, losses in the lens material, spillover and polarization loss are taken into account for antenna gain calculation. The proposed method significantly reduces computing time for multilayered lens in comparison with the most commonly used in antenna design. © 2015 Radio Society (Mauritius)
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