77 research outputs found
Microwave Imaging for Early Breast Cancer Detection
We overview the research trend on microwave imaging for early breast cancer detection. The technologies have two categories: ultra-wide band (UWB) radar that reconstructs the scattering power distribution in the breast and inverse scattering problem that reconstructs the dielectric properties distribution. We have developed a clinical equipment using UWB radar and carried out clinical test 4 years ago. Through the experiments, we concluded that the UWB radar was insufficient for the clinical equipment, because the UWB radar cannot discriminate cancerous tumor and other lesions. Therefore, we have been studying inverse scattering. It is a challenging task to develop an equipment using inverse scattering technologies. We have proposed a microwave mammography that has four features: (1) sensor with breast fixing by absorption, (2) small sensor with multipolarization, (3) image reconstruction program linking the commercial EM simulator, and (4) hybrid imaging method using UWB radar and inverse scattering
Microwave Imaging for Breast Cancer Detection
Microwave imaging (MI) is characterized by no exposure, stronger contrast between soft tissues than X-rays and ultrasound, and a smaller device scale. This chapter describes the electrical properties of the breast tissue that underlie MI, and then outlines the MI hardware configuration and three imaging algorithms: confocal imaging, scattering tomography, and near-field holography. After that, we will introduce the actual equipment and experimental results using the three imaging algorithms. Finally, we will summarize the challenges of realizing a medical imaging device using MI
In-orbit Demonstration of Reaction Control System for Orbital Altitude Change of Micro-Satellite ALE-2
This research presents the results of an in-orbit test of the orbital altitude control for a micro-satellite equipped with the first space-demonstrated high-density small cold gas jet thruster. In the field of micro-satellites, the application of thrusters to practical missions has not yet progressed due to their high cost, mechanical and electrical incompatibility with the satellite bus system, and increased operational risks. By contrast, the demand for orbit control functions has been increasing in recent years with the expansion of micro-satellite applications. The76kg satellite ALE-2 , which was jointly developed by Tohoku University and ALE Co., Ltd., has the world\u27s first challenging mission to artificially generate shooting stars by ejecting small substances (meteor source) from the ejection device fixed on the satellite body. To avoid collision of the ejected meteor source with other flying objects, the mission must be performed in a sun-synchronous orbit at an altitude of less than 400 km, which is lower than that of the International Space Station. However, it is required to maintain the mission orbit autonomously because the orbit decay is large due to the effect of atmospheric drag. In addition, to release the meteor source at an arbitrary orbital position, it is essential to manipulate the ground track by raising and lowering the orbital altitude. Therefore, ALE-2 needs to control the orbit altitude actively and with arbitrary amount of change. In this study, the reaction control system (RCS), which satisfies the orbit change capability, mission requirements, and compatibility with the satellite bus system, is installed on ALE-2 to perform space demonstrations of orbit control and to evaluate the operational performance of the thruster. ALE-2 will be the first to be equipped with a cold gas jet thruster developed by Patched conics, LLC. It is estimated that the thruster is capable of changing altitude more than 1 km by continuous drive for one orbital period. Using this RCS, the following three criteria were set as the evaluation criteria: (Minimum) the orbit altitude can be actively changed by the thruster, (Full) the orbit altitude can be controlled by an arbitrary amount of operation and can be increased more than 1 km per orbit, and (Extra) the mission orbit can be transferred according to the meteor source release plan. ALE-2 was launched on December 6, 2019, and the in-orbit test of the RCS started four months later. Although the RCS was not able to achieve its initial orbit change capability due to an anomaly in the power supply system, various kinds of tests were conducted under conditions that allowed continuous thruster operation. It was confirmed that the orbit altitude was increased by 0.4 km per orbit. In addition, the fault detection, isolation and recovery (FDIR)function was effectively performed against any kinds of anomalies of RCS during in-orbit operation. Therefore, a sustained orbital altitude of 400 km was expected to be achievable using the onboard RCS
ジドウ ソウサホウ ニヨル ガン チリョウヨウ 125 I シード ホウシャセン キョウド ケンテイ システム ノ カイハツ
A new scanning system using a NaI(Tl) scintillation survey meter, copper slit and drive-unit has been
developed for quality control of radioactive seeds. Radioactive seed implants, also called brachytherapy, are
widely used modality in the treatment of early stage prostate cancers. Seeds containing the iodine-125 are most
commonly used for permanent implant prostate brachytherapy. These seeds are commercially available and
delivered in a sterile environment in the form of packaged cartridge. It is impractical to re-sterilize and re-load
seeds after calibration. This paper describes a new method to calibrate all seeds in the seed cartridge in a sterile
package
Problems in three Japanese drug users with Human Immunodeficiency Virus infection
Numbers of individuals infected with Human Immunodeficiency Virus (HIV) are increasing in Japan. The majority of them are Men who have sex with men and a part of them take drugs as ‘Sex drug’ at their sexual intercourse. Especially, Amyl nitrite, Methamphetamine, 5-methoxy-N, N-diisopropyltryptamine (5-MeO-DIPT Foxy), and 3, 4- methylenedioxy- methamphetamine (MDMA Ecstasy) are used, and they sometimes cause the physical and mental disorders. However, the actual drug inducing troubles among Japanese HIV-infected drug users had not yet been discussed enough. In this report, we describe three cases with HIV infection a case developed severe neuroleptic malignant syndrome (NMS) after taking 5-MeO-DIPT, a case with persistent convulsion due to multiple drug intake and a case with rhabdomyolysis due to the nonsubjective methamphetamine intake. Through these cases, we raise and discuss several underlying problems associated with drug use among HIV-infected individuals
The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force
「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection
DOCK2 is involved in the host genetics and biology of severe COVID-19
「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target
Estimation of Propagation Structure by means of Hopfield Neural Network
Meeting Date: 07/08/2001 - 07/13/2001 : Boston, MAautho
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