105 research outputs found

    中性粒子ビーム入射と磁気リコネクションの高出力加熱を用いた超高ベータトーラスプラズマの生成と維持

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    学位の種別:課程博士University of Tokyo(東京大学

    ラット同種肝移植におけるロイトコリエンB[4]受容体拮抗剤の免疫抑制効果

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    取得学位 : 博士(医学), 学位授与番号 : 医博甲第1207号, 学位授与年月日:平成8年3月31日,学位授与年:199

    Diffraction Patterns of the Millimeter Wave with a Helical Wavefront by a Triangular Aperture

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    In this paper, for the first time, we developed the measurement method of the topological charge (TC) in millimeter wave with helical wavefront by a triangular aperture. The millimeter wave with helical wavefront was passively generated by conversion from a Gaussian beam using a spiral mirror, which we also developed. Each diffraction pattern depended on TC, and negative TC and positive TC were symmetric pairs under reflection. These diffraction patterns were perfectly compatible with the calculation results

    JASTRO IC/IS Guideline for Gynecologic Cancers

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    It has been postulated that the combination of intracavitary and interstitial brachytherapy (IC/IS) is effective and safe for large and irregularly shaped uterine cervical cancer patients. However, due to its invasiveness compared to conventional intracavitary brachytherapy (ICBT), it has to be said that the implementation speed of IC/IS is slow. Until now, there have been no guidelines for required equipment, human resources, and procedural guide focusing solely on IC/IS. The purpose of this guideline is to provide radiation oncologists and medical physicists who wish to start IC/IS with practical and comprehensive guidance for a safe IC/IS introduction and to help accelerate the spread of the utilization of IC/IS nationwide. This is the English translation of the Japanese IC/IS Guidelines, and it was created in an effort to share the Japanese approach to the management of locally advanced uterine cervical cancer worldwide

    Prevalence, reasons, and timing of decisions to withhold/withdraw life-sustaining therapy for out-of-hospital cardiac arrest patients with extracorporeal cardiopulmonary resuscitation

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    Background Extracorporeal cardiopulmonary resuscitation (ECPR) is rapidly becoming a common treatment strategy for patients with refractory cardiac arrest. Despite its benefits, ECPR raises a variety of ethical concerns when the treatment is discontinued. There is little information about the decision to withhold/withdraw life-sustaining therapy (WLST) for out-of-hospital cardiac arrest (OHCA) patients after ECPR. Methods We conducted a secondary analysis of data from the SAVE-J II study, a retrospective, multicenter study of ECPR in Japan. Adult patients who underwent ECPR for OHCA with medical causes were included. The prevalence, reasons, and timing of WLST decisions were recorded. Outcomes of patients with or without WLST decisions were compared. Further, factors associated with WLST decisions were examined. Results We included 1660 patients in the analysis; 510 (30.7%) had WLST decisions. The number of WLST decisions was the highest on the first day and WSLT decisions were made a median of two days after ICU admission. Reasons for WLST were perceived unfavorable neurological prognosis (300/510 [58.8%]), perceived unfavorable cardiac/pulmonary prognosis (105/510 [20.5%]), inability to maintain extracorporeal cardiopulmonary support (71/510 [13.9%]), complications (10/510 [1.9%]), exacerbation of comorbidity before cardiac arrest (7/510 [1.3%]), and others. Patients with WLST had lower 30-day survival (WLST vs. no-WLST: 36/506 [7.1%] vs. 386/1140 [33.8%], p ConclusionFor approximately one-third of ECPR/OHCA patients, WLST was decided during admission, mainly because of perceived unfavorable neurological prognoses. Decisions and neurological assessments for ECPR/OHCA patients need further analysis

    Brachytherapy in Japan

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    This study aimed to assess the current state of brachytherapy (BT) resources, practices and resident education in Japan. A nationwide survey was undertaken encompassing 177 establishments facilitating BT in 2022. Questionnaires were disseminated to each BT center, and feedback through online channels or postal correspondence was obtained. The questionnaire response rate was 90% (159/177), and every prefecture had a response in at least one center. The number of centers in each prefecture ranged from 0.6 to 3.6 (median: 1.3) per million population. The annual number of patients in each center ranged from 0 to 272 (median: 31). While most prefectures provided intracavitary (IC) BT for gynecological cancers and interstitial (IS) BT for prostate cancer, only one-third of the prefectures provided IS BT for cancer sites other than the prostate. The institutional image-guided BT implementation rate was 71%. IC and IS BT was performed for 15.4% of IC BT cases of gynecological cancer. Only 47% of the BT training centers answered that they could provide adequate training in BT for residents. The most common reason for this finding was the insufficient number of patients in each center. The results show that, although BT has achieved uniformity in terms of facility penetration, new technologies are not yet widespread enough. Furthermore, IS BT, which requires advanced skills, is limited to a few BT centers, and considerable number of BT training centers do not have sufficient caseloads to provide the necessary experience for their residents

    Development of the calibration method for a fast steering antenna for investigating the mode conversion window used in EBW heating in the LHD plasma

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    In this study, we developed a calibration method for a fast steering antenna for investigating the mode conversion window used in electron Bernstein wave heating in the large helical device. The calibration was carried out in under-dense plasma against a line-of-sight with an optical thickness which varied spatially. Although multi-reflected background radiation becomes dominant in optically thin lines-of-sight, we succeeded in calibrating the fast steering antenna by including the effect of multi-reflected background radiation in the solution of the radiation transfer equation as the constant by which the temperature of the center of the plasma is multiplied. In addition, we report the initial results of experiments investigating the mode conversion window in over-dense plasma using the calibrated antenna

    Hedgehog Promotes Neovascularization in Pancreatic Cancers by Regulating Ang-1 and IGF-1 Expression in Bone-Marrow Derived Pro-Angiogenic Cells

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    http://creativecommons.org/licenses/by/2.0/ PublisherBackground: The hedgehog (Hh) pathway has been implicated in the pathogenesis of cancer including pancreatic ductal adenocarcinoma (PDAC). Recent studies have suggested that the oncogenic function of Hh in PDAC involves signaling in the stromal cells rather than cell autonomous effects on the tumor cells. However, the origin and nature of the stromal cell type(s) that are responsive to Hh signaling remained unknown. Since Hh signaling plays a crucial role during embryonic and postnatal vasculogenesis, we speculated that Hh ligand may act on tumor vasculature specifically focusing on bone marrow (BM)-derived cells. Methodology/Principal Findings: Cyclopamine was utilized to inhibit the Hh pathway in human PDAC cell lines and their xenografts. BM transplants, co-culture systems of tumor cells and BM-derived pro-angiogenic cells (BMPCs) were employed to assess the role of tumor-derived Hh in regulating the BM compartment and the contribution of BM-derived cells to angiogenesis in PDAC. Cyclopamine administration attenuated Hh signaling in the stroma rather than in the cancer cells as reflected by decreased expression of full length Gli2 protein and Gli1 mRNA specifically in the compartment. Cyclopamine inhibited the growth of PDAC xenografts in association with regression of the tumor vasculature and reduced homing of BM-derived cells to the tumor. Host-derived Ang-1 and IGF-1 mRNA levels were downregulated by cyclopamine in the tumor xenografts. In vitro co-culture and matrigel plug assays demonstrated that PDAC cell-derived Shh induced Ang-1 and IGF-1 production in BMPCs, resulting in their enhanced migration and capillary morphogenesis activity. Conclusions/Significance: We identified the BMPCs as alternative stromal targets of Hh-ligand in PDAC suggesting that the tumor vasculature is an attractive therapeutic target of Hh blockade. Our data is consistent with the emerging concept that BM-derived cells make important contributions to epithelial tumorigenesis

    Collective Thomson scattering with 77, 154, and 300 GHz sources in LHD

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    Collective Thomson scattering (CTS) is one of attractive diagnostics for measuring locally and directly the fuel temperature and the velocity distribution of fast ions in fusion plasmas. A mega-watt class source of millimeter or sub-millimeter waves is required to detect a weak scattered radiation superimposed on background radiation owing to electron cyclotron emissions (ECEs) from plasmas. Based on electron cyclotron resonance heating (ECRH) system with the frequencies of 77 GHz and 154 GHz in the Large Helical Device (LHD), the CTS diagnostic system has been developed to measure bulk ion temperatures from a few keV to ∼10 keV and fast ions originated from 180 keV-neutral beam injection in the LHD. The measured CTS spectra and their time evolutions are analyzed with the electrostatic scattering theory. The bulk ion temperatures obtained from CTS spectra increase with the neutral beam injections and decrease with the heating terminated. The velocity map of simulated fast ions explains that the bumps on tail of measured CTS spectra are caused by the co- and counter- fast ions. A new prescription for anisotropic velocity distribution function is proposed. As for 154 GHz bands, the CTS spectrum broadenings for D and H plasmas are distinguished reasonably at the same temperature, and its ion temperatures are comparable to those of the charge exchange recombination spectroscopy. As reactor-relevant diagnostics, a 300 GHz gyrotron and a corresponding receiver system have been implemented in LHD to access high density plasmas with low background ECEs. The recent progress for CTS diagnostics and their spectrum analysis with the probe frequencies of 77 GHz, 154 GHz, and 300 GHz in the LHD experiments is described
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