219 research outputs found

    Plasma Switching by Laser Ablation

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    Estimating dynamics of fern species richness and assemblages for 30 years in Japan capital and along planning belt of linear motor car from Tokyo to Nagoya

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    We surveyed species density of ferns in Musashi (Tokyo and Saitama Prefs.), around capital of Japan, and planning belt of Linea express of 250km from Tokyo to Nagoya during 1997-2017, considering with records 30 years (mainly 1960-1980). The species richness (species richness per 10km X 10km) and similarity of species assemblages represented by species overlap were recorded and calculated between them of the past and present. Recent species richness is about half or less and the similarity ranged 0-48% in Musashi and 20-50% in the similarity along the Linea express planning belt.ArticleForestry Research and Engineering: International Journal. 2(2):68-73 (2018)journal articl

    Characteristics of Advanced Colorectal Cancer Detected by Fecal Immunochemical Test Screening in Participants with a Negative Result the Previous Year

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    Background: There is sufficient evidence to show the mortality reduction effect of colorectal cancer (CRC) screening programs using the fecal occult blood test (FOBT). However, we see cases that are found to be advanced CRC despite yearly FOBT screening. Methods: The aim of this study was to investigate the characteristics of advanced CRC detected by a fecal immunochemical test (FIT) screening program in participants with a negative screening result the previous year, which we call “Negative advanced CRC”. A total of 109,639 participants (10.0% required colonoscopy, of whom 76.9% received one) underwent a CRC screening program using a FIT from fiscal 2009 to 2017. Negative advanced CRC was compared with advanced CRC (First advanced CRC) found at the first visit in a person who had not had a FIT screening history for more than 3 years. In addition, we compared the characteristics of Negative advanced CRC with those of interval cancer: cancer cases detected after a negative screening result and before the date of the next recommended screening. Results: A total of 339 cases of CRC (175 male: 164 female, 173 early stage: 166 advanced stage) were detected in the nine-year CRC screening period. The rate of right-sided CRCs was significantly higher in female (P < 0.01), advanced stage (P < 0.01), negative result previous year (P < 0.01), and symptom-negative (P < 0.01) participants than in each counterpart, respectively. The ratio of female (22/35; 62.9%) patients in Negative advanced CRCs tended to be high compared with that (40/83; 48.2%) in First advanced CRCs (P = 0.145). Overall, 22 (62.9%) of 35 Negative advanced CRCs and 28 (33.7%) of 83 First advanced CRCs were located in the right-sided colon, and the rate was significantly higher in Negative advanced CRCs (P < 0.01). In addition, the frequency of female patients was significantly higher in right-sided Negative advanced CRCs than in right-sided First advanced CRCs (P = 0.03). Conclusion: The characteristics of Negative advanced CRC cases (female and right-sided colon) were similar to those of interval cancer reported so far. In the future, it will be necessary to introduce a screening program that is highly sensitive to right-sided CRC

    Imaging of isotope diffusion using atomic-scale vibrational spectroscopy

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    The spatial resolutions of even the most sensitive isotope analysis techniques based on light or ion probes are limited to a few hundred nanometres. Although vibration spectroscopy using electron probes has achieved higher spatial resolution, the detection of isotopes at the atomic level has been challenging so far. Here we show the unambiguous isotopic imaging of 12C carbon atoms embedded in 13C graphene and the monitoring of their self-diffusion via atomic level vibrational spectroscopy. We first grow a domain of 12C carbon atoms in a preexisting crack of 13C graphene, which is then annealed at 600C for several hours. Using scanning transmission electron microscopy electron energy loss spectroscopy, we obtain an isotope map that confirms the segregation of 12C atoms that diffused rapidly. The map also indicates that the graphene layer becomes isotopically homogeneous over 100 nanometre regions after 2 hours. Our results demonstrate the high mobility of carbon atoms during growth and annealing via selfdiffusion. This imaging technique can provide a fundamental methodology for nanoisotope engineering and monitoring, which will aid in the creation of isotope labels and tracing at the nanoscale

    L-Qモデルは転移性脳腫瘍の定位放射線照射に適用可能か?

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    The biologically effective dose (BED) based on the linear-quadratic (LQ) model has been commonly used to evaluate the dose-effect relationships among the different fractionation schedules, but whether the LQ model is appropriate for hypofractionated (HF) high-dose stereotactic irradiation (STI) is uncertain. The validity of the model at high doses per fraction has been critically examined. In this study, STI of metastatic brain tumors was evaluated to suggest the applicability of the LQ model to HF high-dose radiotherapy. No significant difference was found between stereotactic radiosurgery (SRS) and HF stereotactic radiotherapy (SRT) in the analyses of 151 tumors. Furthermore, no significant differences were found among SRS, HF-SRT, and non-HF SRT in 117 metastatic lung adenocarcinomas. The results of this study suggest that BED calculation is a reasonable approach for careful dose-effect evaluation based on the LQ model for HF high-dose radiotherapy for metastatic brain tumors, especially lung adenocarcinomas.博士(医学)・甲第688号・平成30年9月26

    Trends of correlations between serum levels of growth hormone and insulin-like growth factor-I in general practice

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    Serum levels of growth hormone (GH) and insulin-like growth factor (IGF)-I are crucial in the diagnosis and management of GH-related diseases. However, these levels are affected by nutritional and metabolic status. To elucidate the correlations between GH and IGF-I in various conditions, a retrospective analysis was performed for adult patients in which GH levels were examined by general practitioners during the period from January 2019 to December 2021. Of 642 patients, 33 patients were diagnosed with acromegaly, 21 were diagnosed with GH deficiency (GHD), and 588 were diagnosed with non-GH-related diseases (NGRD). In contrast to the positive correlations found between the levels of GH and IGF-I in patients with acromegaly (R=0.50; P<0.001) and patients with GHD (R=0.39; P=0.08), a negative correlation was found in the NGRD group (R=-0.23; P<0.001). In that group, the results of multivariable analysis showed that GH levels were predominantly influenced by gender and body mass index (BMI), whereas IGF-I levels were modulated by albumin in addition to age and GH. Of note, in the NGRD group, there was an enhanced negative correlation between GH and IGF-I under conditions of BMI < 22 and albumin < 4.0 g/dL (R=-0.45; P<0.001), and the negative correlation between GH and IGF-I was reinforced by excluding patients with other pituitary diseases and patients taking oral steroids (R=-0.51; P<0.001 and R=-0.59; P<0.001, respectively). Collectively, the results indicate that attention should be given to the presence of a negative correlation between serum levels of GH and IGF-I, especially in lean and low-nutritious conditions

    Biological Dose Evaluation Of Radiotherapy By Equivalent Dose In 2Gy Fractions (EQD2) In Recurrent Glioblastoma.

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    The standard treatment for glioblastoma is surgery followed by radiation therapy (RT) and temozolomide (TMZ) chemotherapy. A total dose of 60 Gy given in 2 Gy fractions (fr) with concurrent and adjuvant TMZ has been recommended; however, local recurrences are frequent and the prognosis remains very poor. In this study, the equivalent dose in 2Gy fr (EQD2) at the recurrent site of glioblastoma was assessed to evaluate the biological effect of RT on glioblastoma considering that α/β ratios might vary from 1 to 10 Gy. Recurrences were found in gross tumor volume (GTV) areas in all 11 patients, and 8 of them also showed recurrence in clinical target volume (CTV). Differences in EQD2 according to α/β ratios were relatively small in high-dose areas around 60 Gy; however, low-dose areas often showed significant differences of EQD2 according to the α/β ratios. In patients that received 60 Gy in 2 Gy fr, EQD2 was less than the original physical dose and became smaller as the α/β ratio became smaller. The comparison of the dose distribution of EQD2 and dose volume histogram (DVH) of EQD2 between α/β ratios 1 and 10 suggested that little difference was found in relatively high-dose areas but a significant difference was found in low-dose areas. In contrast, if the fraction size was larger than 2 Gy, EQD2 was greater than the original physical dose and it became larger as the α/β ratio became smaller. In conclusion, this study showed that the standard RT 60 Gy in 2 Gy fr is insufficient for glioblastoma, and it suggested that biological effects might differ significantly according to each fraction size of radiation and α/β ratio of the linear quadratic (LQ) model

    脳幹部転移性脳腫瘍に対する寡分割定位放射線治療の治療成績

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    Background: To assess the neuroimaging and clinical outcomes in patients with brainstem metastasis (BSM) treated with linac-based fractionated stereotactic radiotherapy (fSRT) with a micro-multileaf collimator. Methods: Between May 2007 and January 2017, 24 patients (15 male and 9 female) with BSM (25 lesions: midbrain, 10; pons, 13; and medulla oblongata, 2) were consecutively treated with linac-based fSRT. BSM originated from the lung (n = 18, 75.0%), colon (n = 3, 12.5%), and breast (n = 3, 12.5%). The median patient age was 67.0 (range: 42-80) years. Recursive partition analysis classified 2 patients as class I, 17 as class II, and 5 as class III. Overall survival was calculated using the Kaplan-Meier method. Results: Tumor volume ranged from 0.01 to 7.49 cm3 (median: 0.233 cm3), and patients were treated with a dose of 24-40 Gy in 7-13 fractions. The median OS was 9 months after fSRT (95% confidence interval 4.104-13.896). Large tumor volume, presence of brainstem-related symptoms, poor pretreatment Karnofsky performance status, and recursive partition analysis class III were significantly associated with low overall survival. Tumor volume decreased in 18 metastatic lesions, remained stable in 6, and increased in 1. No patient exhibited permanent radiation injury. Grade 2 nausea and vomiting according to the Common Terminology Criteria for Adverse Events 4.0 occurred in 1 patient who received corticosteroids. Conclusions: Linac-based fSRT with a micro-multileaf collimator delivered in the doses of 24-40 Gy in 7-13 fractions is a safe and effective local therapy for patients with BSM.博士(医学)・乙第1450号・令和2年3月16日Copyright © 2019 Elsevier Inc. All rights reserved

    中枢神経系原発悪性リンパ腫の放射線治療個別化の妥当性と有用性:画像評価を用いた治療効果に基づく放射線治療計画

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    Background: To assess the feasibility and efficacy of individualized treatment selection in radiation therapy (RT) for primary central nervous system lymphoma (PCNSL) according to treatment response by radiographic assessment. Methods: The details of recurrence and change in performance status (PS) were assessed in 31 patients with histologically confirmed PCNSL treated between 2000 and 2016. During the treatment period, radiographic assessment was conducted, and RT planning (RTP) was determined individually by treatment response. Results: At a median follow-up of 28.2 months, 9 patients were alive and 7 of whom were relapse-free. Two-year overall survival (OS) and progression-free survival (PFS) rates were 69.3% and 52.7%, with median survival times (MSTs) of 36.5 months and 24.4 months, respectively. Two-year local recurrence rate was 40.5% and the median time to local recurrence from treatment initiation was 27.9 months. All patients were scheduled to receive whole-brain RT (WBRT) and subsequent partial-brain RT(PBRT), with a median total dose to the tumor bed of 46 Gy and median WBRT dose of 30 Gy. Eight patients received reduced-dose WBRT (rd-WBRT) (<30 GY), and 13 patients who could not achive a complete response (CR) during the RT period received additional boost radiation after WBRT and PBRT, with a median dose of 6 Gy. Over 70% of local recurrence occurred within areas in which only WBRT was conducted (median dose of 30.3 Gy). Two-year occurrence rate of neurotoxicity over grade 2 was 49.5%. PS at 24 months after RT was maintained in 12 patIents. Conclusions: lndividual RTP using radiographic assessment led to reasonable survival and disease control rates with mild treatment-related toxicity. For patients not receiving chemotherapy or lacking a CR after chemotherapy and WBRT, WBRT followed by PBRT and additional boost radiation for poor RT responders might be effective. However, even for patients with CR after chemotherapy, a WBRT dose of 30 Gy or higher might be necessary for local control.博士(医学)・甲第705号・平成31年3月15
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