75 research outputs found

    Size effects in near-ultraviolet Raman spectra of few-nanometer-thick silicon-oninsulator nanofilms

    Get PDF
    We have fabricated Si-on-insulator (SOI) layers with a thickness h1 of a few nanometers and examined them by Raman spectroscopy with 363.8 nm excitation. We have found that phonon and electron confinement play important roles in SOI with h1<10 nm. We have confirmed that the first-order longitudinal optical phonon Raman band displays size-induced major homogeneous broadening due to phonon lifetime reduction as well as minor inhomogeneous broadening due to wave vector relaxation (WVR), both kinds of broadening being independent of temperature. Due to WVR, transverse acoustic (TA) phonons become Raman-active and give rise to a broad band in the range of 100–200 cm 1. Another broad band appeared at 200–400 cm 1 in the spectrum of SOI is attributed to the superposition of 1st order Raman scattering on longitudinal acoustic phonons and 2nd order scattering on TA phonons. Suppression of resonance-assisted 2-nd order Raman bands in SOI spectra is explained by the electron-confinement-induced direct band gap enlargement compared to bulk Si, which is confirmed by SOI reflection spectra. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4947021

    Multi-institutional phase II study on the safety and efficacy of dynamic tumor tracking-stereotactic body radiotherapy for lung tumors

    Get PDF
    Background and purpose: This study aimed to evaluate the safety and efficacy of dynamic tumor tracking-stereotactic body radiotherapy (DTT-SBRT) for lung tumors. Materials and methods: Patients with cStage I primary lung cancer or metastatic lung cancer with an expected range of respiratory motion of ≥10 mm were eligible for the study. The prescribed dose was 50 Gy in four fractions. A gimbal-mounted linac was used for DTT-SBRT delivery. The primary endpoint was local control at 2 years. Results: Forty-eight patients from four institutions were enrolled in this study. Forty-two patients had primary non-small-cell lung cancer, and six had metastatic lung tumors. DTT-SBRT was delivered for 47 lesions in 47 patients with a median treatment time of 28 min per fraction. The median respiratory motion during the treatment was 13.7 mm (range: 4.5–28.1 mm). The motion-encompassing method was applied for the one remaining patient due to the poor correlation between the abdominal wall and tumor movement. The median follow-up period was 32.3 months, and the local control at 2 years was 95.2% (lower limit of the one-sided 85% confidence interval [CI]: 90.3%). The overall survival and progression-free survival at 2 years were 79.2% (95% CI: 64.7%–88.2%) and 75.0% (95% CI: 60.2%–85.0%), respectively. Grade 3 toxicity was observed in one patient (2.1%) with radiation pneumonitis. Grade 4 or 5 toxicity was not observed. Conclusion: DTT-SBRT achieved excellent local control with low incidences of severe toxicities in lung tumors with respiratory motion

    Dynamic tumor-tracking stereotactic body radiotherapy with real-time monitoring of liver tumors using a gimbal-mounted linac: A multi-institutional phase II study

    Get PDF
    [Background and purpose] This prospective multicenter phase II study aimed to evaluate the safety and efficacy of dynamic tumor tracking (DTT) stereotactic body radiotherapy (SBRT) with real-time monitoring of liver tumors using a gimbal-mounted system. [Materials and methods] Patients with < 4 primary or metastatic liver tumors with diameters ≤ 50 mm and expected to have a respiratory motion of ≥ 10 mm were eligible. The prescribed dose was 40 Gy in five fractions. The primary endpoint was local control (LC) at 2 years. The secondary endpoints were overall survival (OS), progression-free survival (PFS), treatment-related toxicity, and tracking accuracy. [Results] Between September 2015 and March 2019, 48 patients (48 lesions) with a median age of 74 years were enrolled from four institutions. Of these, 39 were diagnosed with hepatocellular carcinoma and nine with metastatic liver cancer. The median tumor diameter was 17.5 mm. DTT-SBRT was successfully performed in all patients; the median treatment time was 28 min/fraction. The median follow-up period was 36.5 months. The 2-year LC, OS, and PFS rates were 98.0 %, 88.8 %, and 55.1 %, respectively. Disease progression was observed in 33 (68.8 %) patients. One patient (0.2 %) had local recurrence, 31 (64.6 %) developed new hepatic lesions outside the irradiation field, and nine (18.8 %) had distant metastases (including overlap). Grade 3 late adverse events were observed in seven patients (14.5 %). No grade 4 or 5 treatment-related toxicity was observed. The median tracking accuracy was 2.9 mm. [Conclusion] Employing DTT-SBRT to treat liver tumors results in excellent LC with acceptable adverse-event incidence

    Effect of exercise and/or educational interventions on physical activity and pain in patients with hip/knee osteoarthritis: A systematic review with meta-analysis

    Get PDF
    Objective: To investigate the effectiveness of exercise and/or educational intervention on physical activity and pain in patients with hip/knee osteoarthritis (OA) using systematic review and meta-analysis.Methods: We searched randomized controlled trials that investigated physical activity and pain and compared exercise and/or educational intervention with usual care in patients with hip/knee OA in MEDLINE (PubMed), ProQuest, Scopus, and the Physiotherapy Evidence Database (PEDro), including all those published by April 30, 2022 and written in English. Studies that newly applied analgesics after onset of the intervention were excluded. The revised Cochrane risk-of-bias tool for randomized trials was used to assess the methodological qualities. The random-effects model was used for meta-analysis with standard mean differences using RevMan version 5.4. The body of evidence for each study was synthesized using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.Results: Twenty studies including 2,350 patients were included (7 exercise studies, 8 educational intervention studies and 5 combination studies). The meta-analysis demonstrated that there is very low evidence that combination therapy of exercise and educational intervention improve the physical activity level at the endpoint (4 articles; SMD 0.33, 95% CI 0.04 to 0.51, P = 0.03). Low evidence was observed for combination therapy reducing pain (4 articles; SMD -0.15, 95% CI -0.29 to -0.02, P = 0.03).Discussion: The current evidence indicated that combination therapy of exercise and educational intervention leads to improved physical activity and pain reduction in hip/knee OA patients, but the risk of bias in each study, especially in allocation concealment, downgraded the evidence level. These findings support the use of a combination therapy of exercise and educational intervention to promote physical activity levels in patients with hip/knee OA.Trail registration: There was no financial support for this research. The protocol was registered at the International Prospective Register of Systematic Reviews (registration code: CRD42020205804)

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

    Get PDF
    「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

    Get PDF
    「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

    Observation of Ultrathin Silicon Nitride Surface by Scanning Probe Microscopy

    No full text
    corecore