proton

质子
  • 文章类型: Journal Article
    研究了使用天然靶标的三种不同反应,以从其前体155Dy的衰变中产生用于医学应用的155Tb。TALYS代码已被用来优化横截面描述,并改善与全套可用数据的一致性。该研究是通过两个放射化学分离的理论模型完成的:为生产高质量155Tb样品提供了最佳解决方案,保证不存在主要污染物,156TB。
    Three different reactions with the use of natural targets are investigated to produce 155Tb for medical applications from the decay of its precursor 155Dy. The TALYS code has been exploited to optimize the cross section description and to improve the agreement with the full set of available data. The study is completed by a theoretical model for the two radio-chemical separations: optimal solutions are presented for the production of high quality 155Tb samples, guaranteed by the absence of the main contaminant, 156Tb.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    背景:
辐射诱导的DNA损伤,如单链断裂(SSB),双股断裂(DSB)和复杂DSB(cDSB)是放射生物学的关键方面,对放射治疗和辐射防护应用具有重要意义。
材料和方法:
这项研究对质子(0.5-100MeV/u)的影响进行了彻底的调查,使用Geant4-DNA轨道结构代码结合DBSCAN算法和蒙特卡罗损伤模拟(MCDS)代码对人成纤维细胞DNA上的氦离子(1-100MeV/u)和碳离子(5-480MeV/u)。基于Geant4-DNA的模拟以1μmx1μmx0.5μm水箱为目标,以逐个事件和相互作用位置的三维坐标为基础计算能量沉积,然后使用DBSCAN算法来计算SSB的产量,人成纤维细胞中的DSB和cDSB。这项研究调查了质子的线性能量转移(LET)的影响,氦离子和碳离子对DNA损伤的影响。使用MCDS代码研究了细胞氧合对DNA损伤模式的影响。
结果:
研究表明,DSB和SSB产量受颗粒LET的影响,观察到不同颗粒的不同趋势。细胞氧合是一个关键因素,缺氧细胞表现出降低的SSB和DSB产量,强调细胞氧水平与DNA损伤之间的复杂关系。该研究引入了DSB/SSB比率作为评估辐射诱导的DNA损伤严重程度的信息指标。特别是在较高的LET地区。
结论:
该研究强调了考虑颗粒类型的重要性,LET,和细胞氧合在评估电离辐射的生物效应中。 .
    Background. Radiation-induced DNA damages such as Single Strand Break (SSB), Double Strand Break (DSB) and Complex DSB (cDSB) are critical aspects of radiobiology with implications in radiotherapy and radiation protection applications.Materials and Methods. This study presents a thorough investigation into the effects of protons (0.1-100 MeV/u), helium ions (0.13-100 MeV/u) and carbon ions (0.5-480 MeV/u) on DNA of human fibroblast cells using Geant4-DNA track structure code coupled with DBSCAN algorithm and Monte Carlo Damage Simulations (MCDS) code. Geant4-DNA-based simulations consider 1μm × 1μm × 0.5μm water box as the target to calculate energy deposition on event-by-event basis and the three-dimensional coordinates of the interaction location, and then DBSCAN algorithm is used to calculate yields of SSB, DSB and cDSB in human fibroblast cell. The study investigated the influence of Linear Energy Transfer (LET) of protons, helium ions and carbon ions on the yields of DNA damages. Influence of cellular oxygenation on DNA damage patterns is investigated using MCDS code.Results. The study shows that DSB and SSB yields are influenced by the LET of the particles, with distinct trends observed for different particles. The cellular oxygenation is a key factor, with anoxic cells exhibiting reduced SSB and DSB yields, underscoring the intricate relationship between cellular oxygen levels and DNA damage. The study introduced DSB/SSB ratio as an informative metric for evaluating the severity of radiation-induced DNA damage, particularly in higher LET regions.Conclusions. The study highlights the importance of considering particle type, LET, and cellular oxygenation in assessing the biological effects of ionizing radiation.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Clinical Trial Protocol
    背景:肿瘤手术切除是四肢和躯干软组织肉瘤(STS)的标准护理,通常伴有术前或术后放射治疗(RT)。术前RT可以降低关节僵硬和纤维化的风险,但伤口并发症的发生率更高。低分割,在前瞻性试验中,术前RT可提供可接受的结果.质子束疗法(PBT)提供了减少对周围危险器官的剂量的手段,比如皮肤,骨头,软组织,和相邻接头,尚未在四肢和躯干肉瘤患者中进行研究。
    方法:我们的研究名为“术前低分割原始N治疗四肢和Truncal软组织sarcOma(PRONTO)的前瞻性II期试验”是非随机的,前瞻性II期试验评估术前安全性和有效性,计划进行手术切除的四肢和躯干STS患者的高分割PBT。将包括东部合作组表现状态≤2的可切除四肢和躯干STS的成年患者,目的是增加40名患者。治疗将包括30Gy放射生物学等效的PBT,每隔一天交付5个部分,随后2-12周后进行手术切除。主要结果是根据加拿大国家癌症研究所Sarcoma2(NCIC-SR2)多中心试验定义的主要伤口并发症的发生率。次要目标包括晚期≥2级毒性的发生率,1年和2年无局部复发生存率和无远处转移生存率,功能结果,生活质量,和病理反应。
    结论:PRONTO代表了评价在STS中使用低分割PBT的第一个试验。我们的目标是证明这种方法的安全性和有效性,并将我们的结果与先前试验确定的历史结果进行比较。鉴于质子中心数量少,可用性有限,PBT的短期疗程可能为治疗患者提供了机会,否则这些患者在几周内每天接受RT治疗时会受到限制.我们希望这项试验将导致转诊模式的增加,为患者提供便利和临床工作流程效率,并提供支持在此设置中使用PBT的证据。
    背景:NCT05917301(注册23/6/2023)。
    BACKGROUND: Oncologic surgical resection is the standard of care for extremity and truncal soft tissue sarcoma (STS), often accompanied by the addition of pre- or postoperative radiation therapy (RT). Preoperative RT may decrease the risk of joint stiffness and fibrosis at the cost of higher rates of wound complications. Hypofractionated, preoperative RT has been shown to provide acceptable outcomes in prospective trials. Proton beam therapy (PBT) provides the means to decrease dose to surrounding organs at risk, such as the skin, bone, soft tissues, and adjacent joint(s), and has not yet been studied in patients with extremity and truncal sarcoma.
    METHODS: Our study titled \"PROspective phase II trial of preoperative hypofractionated protoN therapy for extremity and Truncal soft tissue sarcOma (PRONTO)\" is a non-randomized, prospective phase II trial evaluating the safety and efficacy of preoperative, hypofractionated PBT for patients with STS of the extremity and trunk planned for surgical resection. Adult patients with Eastern Cooperative Group Performance Status ≤ 2 with resectable extremity and truncal STS will be included, with the aim to accrue 40 patients. Treatment will consist of 30 Gy radiobiological equivalent of PBT in 5 fractions delivered every other day, followed by surgical resection 2-12 weeks later. The primary outcome is rate of major wound complications as defined according to the National Cancer Institute of Canada Sarcoma2 (NCIC-SR2) Multicenter Trial. Secondary objectives include rate of late grade ≥ 2 toxicity, local recurrence-free survival and distant metastasis-free survival at 1- and 2-years, functional outcomes, quality of life, and pathologic response.
    CONCLUSIONS: PRONTO represents the first trial evaluating the use of hypofractionated PBT for STS. We aim to prove the safety and efficacy of this approach and to compare our results to historical outcomes established by previous trials. Given the low number of proton centers and limited availability, the short course of PBT may provide the opportunity to treat patients who would otherwise be limited when treating with daily RT over several weeks. We hope that this trial will lead to increased referral patterns, offer benefits towards patient convenience and clinic workflow efficiency, and provide evidence supporting the use of PBT in this setting.
    BACKGROUND: NCT05917301 (registered 23/6/2023).
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    由于质子疗法具有良好的物理和生物学特性,因此已成为肿瘤放射治疗的有利方式。然而,这种疗法通过初级束之间的核反应产生诱导的放射性,次级粒子,和周围的材料。这项研究的重点是系统地研究笔形波束扫描过程中龙门室内的放射性,利用实验测量和蒙特卡罗模拟。结果表明,患者是诱发放射性的主要来源,主要生产放射性核素,如11C,13N,15o长期照射主要产生放射性核素,如22Na,24Na,和54Mn等。此外,这项研究估计了医务人员在龙门室接受的个人剂量,患者护送的照射剂量,以及残余辐射对患者的额外剂量。最后,该研究提供了建议,以最大程度地减少对医务人员的不必要照射剂量,病人护送,和病人。
    Proton therapy has emerged as an advantageous modality for tumor radiotherapy due to its favorable physical and biological properties. However, this therapy generates induced radioactivity through nuclear reactions between the primary beam, secondary particles, and surrounding materials. This study focuses on systematically investigating the induced radioactivity in the gantry room during pencil beam scanning, utilizing both experimental measurements and Monte Carlo simulations. Results indicate that patients are the primary source of induced radioactivity, predominantly producing radionuclides such as 11C, 13N, and 15O. Long-term irradiation primarily generates radionuclides like 22Na, 24Na, and 54Mn etc. Additionally, this study estimates the individual doses received by medical workers in the gantry room, the irradiation dose for patient escorts, and the additional dose to patients from residual radiation. Finally, the study offers recommendations to minimize unnecessary irradiation doses to medical workers, patient escorts, and patients.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在治疗前获得事先授权(PA)在肿瘤学中变得越来越麻烦,尤其是放射肿瘤学.这里,我们描述了在美国大型学术质子治疗中心进行的战略性新操作PA重新设计的影响,以缩短授权时间并改善患者获得癌症治疗的机会.我们询问这样的重新设计是否可以在肿瘤中心复制和采用。
    我们的PA重新设计策略基于3层方法。具体来说,我们(1)要求付款人对法律支持的时间表负责,(2)保险政策和实践方面的杠杆专业知识,和(3)更新了提交,上诉写作,以及PA的规划程序。在以下3个时间点比较指标:6个月前,在分阶段,干预后6个月。
    在分析改善PA获得护理的影响时,商业质子束治疗的批准百分比在干预后绝对提高了30.6%(P<.001).接受质子束治疗的商业保险患者比例也增加了6.2%,新开始的人数增加了11.7名患者/个月。总体患者普查增加了13名患者/d。中间授权时间为1周,90%接受调查的提供者报告PA负担减轻,患者护理改善.
    这是第一次验证,全面的操作策略,以改善获得癌症治疗的机会,同时减轻PA的负担。这种新颖的方法可能有助于解决医学和外科肿瘤学中PA的障碍,因为重新设计是基于跨学科规范PA的法律。
    UNASSIGNED: Obtaining prior authorization (PA) before treatment is becoming increasingly burdensome in oncology, especially in radiation oncology. Here, we describe the impact of a strategic novel operational PA redesign to shorten authorization time and to improve patient access to cancer care at a large United States academic proton therapy center. We ask whether such a redesign may be replicable and adoptable across oncology centers.
    UNASSIGNED: Our PA redesign strategy was based on a 3-tiered approach. Specifically, we (1) held payors accountable to legally backed timelines, (2) leveraged expertise on insurance policies and practices, and (3) updated the submission, appeal writing, and planning procedures for PA. Metrics were compared at the following 3 time points: 6 months before, at phase-in, and at 6 months after intervention.
    UNASSIGNED: In analyzing the impact of improving PA access to care, the percentage of approvals for commercial proton beam therapy improved by an absolute 30.6% postintervention (P < .001). The proportion of commercially insured patients treated with proton beam therapy also increased by 6.2%, and the number of new starts rose by 11.7 patients/mo. Overall patient census increased by 13 patients/d. Median authorization time was 1 week, and 90% of surveyed providers reported reduced PA burden and improved patient care.
    UNASSIGNED: This is the first validated, comprehensive operational strategy to improve access to cancer therapy while reducing the burden of PA. This novel approach may be helpful for addressing barriers to PA in medical and surgical oncology because the redesign is predicated on laws that regulate PA across disciplines.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    目的:本研究的目的是阐明复发性斜坡脊索瘤的详细临床过程和每种治疗方式的结果。
    方法:对复发性斜坡脊索瘤患者进行单中心回顾性分析。该队列是从接受手术的人中确定的,立体定向放射外科,或在1990年至2022年间在作者机构进行质子治疗。
    结果:在中位(四分位距[IQR])随访43(18-79)个月的40例患者中,共发现95例复发。诊断时的中位年龄(IQR)为48(36-62)岁,55%的患者为男性。23例患者在首次复发前接受手术治疗,然后进行辅助放疗。每位患者复发的中位数(范围)为2(1-8),首次复发的中位(IQR)时间为29(9-51)个月.用以下一种或多种疗法治疗复发:手术,辐射,全身治疗,和激光间质热疗(LITT)。对25例患者进行了44次复发的手术。28例患者采用放射治疗42例复发。手术加放疗治疗复发的患者无进展生存期(PFS)最长(中位[95%CI]总生存期[OS]120[0-245]个月,p<0.01,对数秩检验)。复发但未接受过放疗的患者的PFS比接受过放疗的患者更长。首次复发后的中位(95%CI)OS为68(54-82)个月,首次复发后5年OS为48%,10年OS为27%。多因素Cox回归分析显示首次复发后死亡率与无辅助放疗显著相关(HR0.149,95%CI0.038-0.59,p=0.0067),首次复发时年龄较大(HR1.04,95%CI1.01-1.08,p=0.021),和总复发次数(p=0.032)。7名患者接受了全身治疗,自全身治疗开始以来,这些患者的中位(95%CI)OS为31(11-51)个月。6例患者(15%)使用了伊马替尼和/或纳武单抗。一名患者(3%)因第四次复发而接受LITT治疗。
    结论:尽管复发性脊索瘤具有侵袭性,29例患者中有14例(48%)在初次复发后使用联合疗法存活超过5年。多种治疗选择可能有助于这种顽固性肿瘤患者的长期生存。
    OBJECTIVE: The objective of this study was to clarify the detailed clinical course of recurrent clival chordoma and the outcomes of each treatment modality.
    METHODS: A single-center retrospective analysis was conducted on patients seen for recurrent clival chordoma. The cohort was identified from those who underwent surgery, stereotactic radiosurgery, or proton therapy at the authors\' institution between 1990 and 2022.
    RESULTS: A total of 95 recurrences in 40 patients with a median (interquartile range [IQR]) follow-up of 43 (18-79) months were identified. The median (IQR) age at the time of diagnosis was 48 (36-62) years, and 55% of patients were male. Twenty-three patients were treated with surgery followed by adjuvant radiation before the first recurrence. The median (range) number of recurrences per patient was 2 (1-8), and the median (IQR) time to the first recurrence was 29 (9-51) months. The recurrences were treated with one or more of the following therapies: surgery, radiation, systemic therapy, and laser interstitial thermal therapy (LITT). Surgery was performed for 44 recurrences in 25 patients. Radiation was used to treat 42 recurrences in 28 patients. Patients with recurrences treated with surgery plus radiation had the longest progression-free survival (PFS) (median [95% CI] overall survival [OS] 120 [0-245] months, p < 0.01, log-rank test). Patients with recurrences but without prior radiation had longer PFS than those patients with prior radiation. The median (95% CI) OS after the first recurrence was 68 (54-82) months, 5-year OS after the first recurrence was 48%, and 10-year OS was 27%. Multivariate Cox regression analysis showed that mortality after the first recurrence was significantly associated with no adjuvant radiation (HR 0.149, 95% CI 0.038-0.59, p = 0.0067), older age at the time of the first recurrence (HR 1.04, 95% CI 1.01-1.08, p = 0.021), and total number of recurrences (p = 0.032). Seven patients received systemic therapy, and the median (95% CI) OS of these patients since initiation of systemic therapy was 31 (11-51) months. Imatinib and/or nivolumab were used in 6 patients (15%). One patient (3%) was treated with LITT for his fourth recurrence.
    CONCLUSIONS: Despite the aggressive nature of recurrent chordoma, 14 of 29 patients (48%) survived for more than 5 years after the initial recurrence using combined therapies. Multiple treatment options may contribute to the long-term survival of patients with this intractable tumor.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    目的:患者有时会在放射治疗(RT)期间报告磷酸盐和幻影。然而,细节特征和相关因素还没有得到很好的理解。我们的前瞻性研究旨在调查幻影和磷的特征,为了确定影响发生的因素,RT期间此类感觉的强度和享乐(愉悦/不愉快)评级。
    方法:我们共纳入106名患者(37名女性),在大脑区域接受RT的人,耳朵,鼻子,喉部(ENT),和身体的其他区域,持续时间为43±5天。在结构化医学访谈中收集病史和治疗参数。使用Sniffin棒气味鉴定试验在基线测量嗅觉功能。每周根据自我报告问卷记录Phantosmia和磷酸化。
    结果:有37%的患者出现幻影,51%的人经历过磷烯,29%的人同时经历这两种感觉。膦通常被认为是一种耀眼的蓝色,白色和/或紫色光,幻影通常被认为是一种化学物质,金属或烧焦的气味。年龄较小(F=7.81,p<0.01),脑区辐射(χ2=14.05,p=0.02),没有味觉问题(χ2=10.28,p=0.01),和质子RT(χ2=10.57,p=0.01)与这些异常感觉有关。化学/粉尘暴露史预示着幻影的强度降低(B=-1.52,p=0.02)和不愉快程度降低(B=0.49,p=0.03)。相比之下,疾病(肿瘤)持续时间(B=0.11,p<0.01),食物过敏(B=2.77,p<0.01),癫痫(B=-1.50,p=0.02)影响磷强度。镇痛药的摄入预测了磷的更高的愉悦度(B=0.47,p<0.01)。
    结论:在RT期间常见幻象和磷。治疗设置和个体唤醒水平影响发生,这种异常感觉的强度和快感。Phandosmias和phosphenes可能涉及更多的中枢神经而不是外周机制,它们可以通过激活不被认为是嗅觉或视觉网络一部分的区域来引发。
    Patients sometimes report phosphene and phantosmia during radiation therapy (RT). However, the detail features and related factors are not well understood. Our prospective study aimed to investigate the characteristics of phantosmias and phosphenes, to identify factors that influence the occurrence, intensity and hedonic (pleasantness/unpleasantness) ratings of such sensations during RT.
    We included a total of 106 patients (37 women), who underwent RT in regions of the brain, ear, nose, throat (ENT), and other areas of the body for a duration of 43 ± 5 days. Medical history and treatment parameters were collected in a structured medical interview. Olfactory function was measured using the Sniffin\' Stick Odor Identification Test at baseline. Phantosmia and phosphene were recorded weekly based on a self-report questionnaire.
    There were 37% of the patients experiencing phantosmias, 51% experiencing phosphenes, and 29% simultaneously experiencing both sensations. Phosphenes were typically perceived as a flashily blue, white and/or purple light, phantosmias were typically perceived as a chemical-like, metallic or burnt smell. Younger age (F = 7.81, p < 0.01), radiation in the brain region (χ2 = 14.05, p = 0.02), absence of taste problems (χ2 = 10.28, p = 0.01), and proton RT (χ2 = 10.57, p = 0.01) were related to these abnormal sensations. History of chemical/dust exposure predicted lower intensity (B = -1.52, p = 0.02) and lower unpleasantness (B = 0.49, p = 0.03) of phantosmia. In contrast, disease (tumor) duration (B = 0.11, p < 0.01), food allergy (B = 2.77, p < 0.01), and epilepsy (B = -1.50, p = 0.02) influence phosphenes intensity. Analgesics intake predicted a higher pleasantness of the phosphenes (B = 0.47, p < 0.01).
    Phantosmias and phosphenes are common during RT. The treatment settings and individual arousal level influence the occurrence, intensity and hedonic of such abnormal sensations. Phantosmias and phosphenes may involve more central neural than peripheral mechanism, and they could be elicited with activation of areas that are not regarded to be part of the olfactory or visual network.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    背景:质子治疗高危前列腺癌(HRPC)的数据有限。使用质子协作组前瞻性注册表,我们评估了接受质子治疗的HRPC患者的结局.
    方法:选择了2009年8月至2019年3月在9个机构接受质子治疗的605名局部HRPC男性。检查的结果包括无进展(FFP),无转移生存率(MFS),总生存期(OS),和毒性。多变量cox/二项回归模型用于评估FFP和毒性的预测因子。
    结果:中位年龄为71岁。格里森第4级(49.4%)和第5级(31.7%)最常见,临床分期T1c(46.1%)和cT2(41.3%)。治疗前前列腺特异性抗原(PSA)的中位数为9.18,国际前列腺症状评分(IPSS)的中位数为6。雄激素剥夺治疗占63.6%。44个部分的中位剂量为79.2GyE。58.2%的病例治疗盆腔淋巴结。使用铅笔束扫描的比例为54.5%,均匀扫描38.8%,直肠垫片占14.2%。在22个月的中位随访中,3年和5年FFP分别为90.7%和81.4%,分别。五年MFS和OS分别为92.8%和95.9%,分别。FFP的独立相关性包括Gleason≥8、PSA>10和cT2(均p<0.05)。未报告4级或5级不良事件。有23(5%)2级和0级3级胃肠道事件。晚期3级,晚期2级,急性3级和急性2级泌尿生殖系统毒性的患病率为1.7%,5.8%,0%,和21.8%,分别。2年2级和3级勃起功能障碍的患病率分别为48.4%和8.4%,分别。
    结论:在迄今为止出版的最大系列中,我们的结果表明,质子治疗HRPC的早期结局在安全性和有效性方面都令人鼓舞.需要进一步评估以确定在该群体中使用质子是否存在优于其他辐射技术的优势。
    Data for proton therapy in high-risk prostate cancer (HRPC) are limited. Using the Proton Collaborative Group prospective registry, we evaluated outcomes for HRPC patients treated with proton therapy.
    A totsl of 605 men with localized HRPC treated with proton therapy from 8/2009 to 3/2019 at nine institutions were selected. Outcomes examined included freedom from progression (FFP), metastasis free survival (MFS), overall survival (OS), and toxicity. Multivariable cox/binomial regression models were used to assess predictors of FFP and toxicity.
    Median age was 71 years. Gleason grade groups 4 (49.4%) and 5 (31.7%) were most common, as were clinical stage T1c (46.1%) and cT2 (41.3%). The median pretreatment prostate specific antigen (PSA) was 9.18 and median International Prostate Symptom Score (IPSS) was 6. Androgen deprivation therapy was given in 63.6%. Median dose was 79.2 GyE in 44 fractions. Pelvic lymph nodes were treated in 58.2% of cases. Pencil beam scanning was used in 54.5%, uniform scanning in 38.8%, and a rectal spacer in 14.2%. At a median followup of 22 months, the 3- and 5-year FFP were 90.7% and 81.4%, respectively. Five-year MFS and OS were 92.8% and 95.9%, respectively. Independent correlates of FFP included Gleason ≥8, PSA > 10, and cT2 (all p < 0.05). No grade 4 or 5 adverse events were reported. There were 23 (5%) grade 2 and 0 grade 3 gastrointestinal events. Prevalence of late grade 3, late grade 2, acute grade 3, and acute grade 2 genitourinary toxicity was 1.7%, 5.8%, 0%, and 21.8%, respectively. Prevalence of grade 2 and 3 erectile dysfunction at 2 years was 48.4% and 8.4%, respectively.
    In the largest series published to date, our results suggest early outcomes using proton therapy for HRPC are encouraging for both safety and efficacy. Further evaluation is needed to determine if an advantage exists to use protons over other radiation techniques in this population.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    近来电力电子器件的应用环境向高辐射环境的扩展将由于由宇宙射线照射引起的充电而导致电力电子器件中使用的绝缘材料的劣化。充电现象应引起电力电子设备的故障。因此,重要的是要了解用质子辐照的绝缘材料的绝缘特性,电子,等。,提高电力电子的可靠性。关于上述,关于质子束辐照的绝缘材料的RIC(辐射诱导电导率)的报道很少。在本文中,我们通过实验评估了在各种辐照条件下用质子束辐照的PI(聚酰亚胺)薄膜的RIC。我们还研究了一种估算PI实测RIC的计算方法。因此,我们澄清了PI的总电导率在非穿透辐照条件下增加,在穿透辐照条件下饱和。原因是辐照能量越高,非穿透辐照条件下的最大质子穿透深度越深。另一方面,由于穿透深度与样品厚度相同,因此在穿透条件下导电特性没有变化。我们还开发了一种计算方法来估算用质子束辐照的整个PI的电导率。通过上述方法计算的估计数据与大多数辐照能量条件下的测量数据进行分析拟合。建议上述计算方法可以估算质子束辐照的整个PI的电导率,无论穿透或非穿透照射,基于RIC和在穿透条件下辐照的PI剂量率之间的关系。在未来,我们将把这项研究的结果纳入绝缘材料内部空间电荷积累的计算模型,以验证质子辐照引起的RIC对空间电荷积累的影响。
    The recent expansion of the application environment of power electronics to high-radiation environments will cause the deterioration of insulation materials used in power electronics due to charging caused by cosmic ray irradiation. The charging phenomena should induce malfunctions in power electronics. Therefore, it is important to understand the insulation characteristics of insulation materials irradiated with protons, electrons, etc., to improve the reliability of power electronics. With respect to the above, there are few reports on the RIC (radiation-induced conductivity) of insulation materials irradiated with proton beams. In this paper, we experimentally evaluated the RIC of PI (polyimide) films irradiated with proton beams under various irradiation conditions. We also studied a calculation method to estimate the measured RIC of the PI. As a result, we clarified that the total conductivity of the PI increased under non-penetrating irradiation conditions and saturated under penetrating irradiation conditions. The reason for this is that the higher the irradiation energy, the deeper the maximum proton penetration depth under non-penetrating irradiation conditions. On the other hand, the conductivity characteristics did not change under penetrating conditions because the penetration depth was the same as the sample thickness. We also developed a calculation method to estimate the conductivity of the entire PI irradiated with proton beams. The estimated data calculated by the above method were analytically fitted with the measured data for most irradiation energy conditions. It is suggested that the above calculation method can estimate the conductivity of the entire PI irradiated with proton beams, regardless of penetrating or non-penetrating irradiation, based on the relationship between the RIC and dose rate of the PI irradiated under penetrating conditions. In the future, we will incorporate the results of this study into a computational model of space charge accumulation inside insulation materials to verify the influence of the RIC caused by proton irradiation on space charge accumulation.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    背景:自由呼吸1H通气MRI显示出希望,但仅针对囊性纤维化(CF)患者的直接肺通气成像方法进行了单中心验证。
    目的:使用在两个中心获得的数据,研究129Xe和1H通气图像之间的关系。
    方法:序列比较。
    方法:中心1;24例CF患者(12例女性),年龄9-47岁。中心2;CF患者7例(女性6例),年龄13-18岁,和6名健康对照(6名女性),年龄21-31岁。在每个中心获得不同患者的数据。
    未经评估:1.5T,三维稳态自由进动和二维变质梯度回波。
    结果:对受试者进行了129Xe通气和1H自由呼吸MRI扫描,并进行了肺功能检查。使用线性分箱计算通气缺陷百分比(VDP),并通过H.M.对图像进行视觉评估。L.J.S.,和G.J.C.(10、5和8年的经验)。
    方法:对129XeVDP,1HVDP,FEV1,LCI。对129XeVDP和1HVDP进行Bland-Altman分析。使用单向ANOVA或Kruskal-Wallis检验评估指标的差异。
    结果:129XeVDP和1HVDP彼此密切相关(r=0.84),FEV1z分数(129XeVDPr=-0.83,1HVDPr=-0.80),和LCI(129XeVDPr=0.91,1HVDPr=0.82)。来自两个中心的129XeVDP和1HVDP的Bland-Altman分析具有0.07%的偏倚和-16.1%和16.2%的一致性界限。129Xe和1HVDP之间VDP与FEV1的线性回归关系无显著差异(P=0.08)。129XeVDP与LCI的关系强于1HVDP。
    结论:1H通气MRI显示与129Xe通气MRI在已确诊肺部疾病的CF患者中的大规模一致性,但在早期肺部疾病患者中可能对细微的通气变化不太敏感。
    方法:2技术效果:阶段2。
    Free-breathing 1 H ventilation MRI shows promise but only single-center validation has yet been performed against methods which directly image lung ventilation in patients with cystic fibrosis (CF).
    To investigate the relationship between 129 Xe and 1 H ventilation images using data acquired at two centers.
    Sequence comparison.
    Center 1; 24 patients with CF (12 female) aged 9-47 years. Center 2; 7 patients with CF (6 female) aged 13-18 years, and 6 healthy controls (6 female) aged 21-31 years. Data were acquired in different patients at each center.
    1.5 T, 3D steady-state free precession and 2D spoiled gradient echo.
    Subjects were scanned with 129 Xe ventilation and 1 H free-breathing MRI and performed pulmonary function tests. Ventilation defect percent (VDP) was calculated using linear binning and images were visually assessed by H.M., L.J.S., and G.J.C. (10, 5, and 8 years\' experience).
    Correlations and linear regression analyses were performed between 129 Xe VDP, 1 H VDP, FEV1 , and LCI. Bland-Altman analysis of 129 Xe VDP and 1 H VDP was carried out. Differences in metrics were assessed using one-way ANOVA or Kruskal-Wallis tests.
    129 Xe VDP and 1 H VDP correlated strongly with; each other (r = 0.84), FEV1 z-score (129 Xe VDP r = -0.83, 1 H VDP r = -0.80), and LCI (129 Xe VDP r = 0.91, 1 H VDP r = 0.82). Bland-Altman analysis of 129 Xe VDP and 1 H VDP from both centers had a bias of 0.07% and limits of agreement of -16.1% and 16.2%. Linear regression relationships of VDP with FEV1 were not significantly different between 129 Xe and 1 H VDP (P = 0.08), while 129 Xe VDP had a stronger relationship with LCI than 1 H VDP.
    1 H ventilation MRI shows large-scale agreement with 129 Xe ventilation MRI in CF patients with established lung disease but may be less sensitive to subtle ventilation changes in patients with early-stage lung disease.
    2 TECHNICAL EFFICACY: Stage 2.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

公众号