49 research outputs found

    Three Dimensional Magnetohydrodynamical Simulations of Core Collapse Supernova

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    We show three-dimensional magnetohydrodynamical simulations of core collapse supernova in which the progenitor has magnetic fields inclined to the rotation axis. The simulations employed a simple empirical equation of state in which the pressure of degenerate gas is approximated by piecewise polytropes for simplicity. Neither energy loss due to neutrino is taken into account for simplicity. The simulations start from the stage of dynamical collapse of an iron core. The dynamical collapse halts at t t = 189 ms by the pressure of high density gas and a proto-neutron star (PNS) forms. The evolution of PNS was followed about 40 milli-seconds in typical models. When the initial rotation is mildly fast and the initial magnetic fields are mildly strong, bipolar jets are launched from an upper atmosphere (r60km r \sim 60 {\rm km} ) of the PNS. The jets are accelerated to 3×104 \sim 3 \times 10 ^4 km s1^{-1}, which is comparable to the escape velocity at the foot point. The jets are parallel to the initial rotation axis. Before the launch of the jets, magnetic fields are twisted by rotation of the PNS. The twisted magnetic fields form torus-shape multi-layers in which the azimuthal component changes alternately. The formation of magnetic multi-layers is due to the initial condition in which the magnetic fields are inclined with respect to the rotation axis. The energy of the jet depends only weakly on the initial magnetic field assumed. When the initial magnetic fields are weaker, the time lag is longer between the PNS formation and jet ejection. It is also shown that the time lag is related to the Alfv\'en transit time. Although the nearly spherical prompt shock propagates outward in our simulations, it is ...Comment: 41 pages, 24 figures, 4 tables, accepted for publication in ApJ. The high resolution version is available at http://www.astro.phys.s.chiba-u.ac.jp/~mikami/research

    Field Survey of Flank Collapse and Run-up Heights due to 2018 Anak Krakatau Tsunami

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    Dataset: https://data.4tu.nl/articles/dataset/Bathymetry_data_underlying_the_publication_Field_survey_of_flank_collapse_and_run-up_heights_due_to_the_2018_Anak_Krakatau_Tsunami/1421561

    Physical Image Quality of Rapid Processing Films

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    The imaging properties of Konica "new" SR series films and "old" MG-SR series films for rapid processing were measured in combination with green-emitting intensifying screens. The measured image quality prarameters include: characteristic curve, modulation transfer function (MTF) and Wiener spectrum. The relative speeds of the new SR series systems were slower than those of the old MG-SR series systems from 10 to 25%. The MTF's of the new systems were generally comparable to those of the old systems, except that SR-G system was improved with an increase of approximately 10%. In the Wiener spectrum measurement, however, the new systems showed from 10 to 35% decrease in low-frequency noise

    Granularity of Asymmetric Screen-Film System

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    非対称増感紙フィルム系について、両面乳剤フィルムのウィナースペクトル測定に及ぼす影響を検討した。濃度0.5~2.5のノイズ試料のフロント乳剤、バック乳剤、支持体層それぞれで測定したスペクトルの和と、両面同時に測定した全スペクトルとを比較した。その結果、全ウィナースペクトルの値は、フロント乳剤、バック乳剤の和より高くなった。また、試料濃度が高いほど、その差は大きくなった。これらは、マイクロデンシトメータの光学系の配置と両面乳剤フィルムの構造に起因している。したがって、非対称システムのようにフィルムの前面と後面で特性を分けて考える場合、注意を要する。We have examined a factor affecting the Wiener spectrum measurement of double-emulsion film. An asymmetric screen-film system (Kodak HC/INSIGHT system) was used in this study. The results indicated that the total Wiener spectra of double-emulsion films are higher than the sum of spectra obtained with the front emulsion and back emulsion separately. These differences are attributed to the arrangement of the optical system of the microdensitometer used to measure and the structure of double-emulsion film

    複数の埋伏過剰歯を伴った石灰化嚢胞性歯原性腫瘍の1例

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    石灰化嚢胞性歯原性腫瘍(以下CCOT)は病理組織学的に,裏装上皮内にghost cellの出現とそれらの石灰化を特徴とし,また,歯牙腫をはじめとする歯原性腫瘍を合併することがある.さらに,CCOT症例の半数前後は埋伏歯を伴うことが知られているが,複数の埋伏過剰歯を伴うことは稀である。今回われわれは,歯牙腫と8本の埋伏過剰歯を伴ったCCOTの1例を経験したので,その概要を報告する.症例は40歳代の男性で,近歯科医院を受診した際にX線検査にて右側上顎洞部に嚢胞様透過像が認められ,精査・加療目的に当科紹介となった.初診時,上顎右側側切歯から右側第一大臼歯部の頬側歯肉に弾性軟の腫脹を認め,波動が触知された.CTにて,右側上顎洞および鼻腔の下部に境界明瞭で単胞性の嚢胞様病変を認め,病変内部に大小の石灰化像および歯牙様石灰化像を認めた.全身麻酔下にて摘出術および対孔形成術を施行した.摘出組織ではCCOTとともに歯牙腫ならびに8本の埋伏歯を認めた.病理組織学的に上皮層内にghost cellとその石灰化がみられた.文献的に本症例のように複数の埋伏過剰歯を伴ったCCOTはきわめてまれであった.It is well known that an associated impacted tooth is seen in about half of cases with calcifying cystic odontogenic tumor (CCOT), but CCOT with two or more impacted teeth is extremely rare. This paper reports a case of CCOT with 8 impacted, supernumerary teeth. The patient is an adult male with swelling of right maxilla. X-ray examination showed a cystic lesion with calcification and with numerous impacted, supernumerary teeth. A clinical diagnosis of CCOT with odontoma was made. And surgical excised of the lesion was performed. Macroscopically, surgically excised specimen showed eight supernumerary teeth with formal and/or unformal shape were involved in the lesion, but these teeth were not enclosed by fibrous capsule. The lesion was diagnosed finally as CCOT with odontoma and with eight impacted, supernumerary teeth by pathological examination. The review of the literature yielded CCOT with more than 3 associated supernumerary has not been documental

    Risk Factors for Bleeding After Endoscopic Submucosal Dissection for Gastric Cancer in Elderly Patients Older Than 80 Years in Japan.

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    Introduction:As the aging of people in a society advances, the number of elderly patients older than 80 years in Japan with gastric cancer continues to increase. Although delayed ulcer bleeding is a major adverse event after endoscopic submucosal dissection (ESD), little is known about characteristic risk factors for bleeding in elderly patients undergoing ESD. This study aimed to evaluate risk factors for delayed bleeding after ESD for gastric cancer in elderly patients older than 80 years.Methods:We retrospectively evaluated the incidence of delayed bleeding after ESD in 10,320 patients with early-stage gastric cancer resected by ESD between November 2013 and January 2016 at 33 Japanese institutions and investigated risk factors for delayed bleeding in elderly patients older than 80 years.Results:The incidence of delayed bleeding in elderly patients older than 80 years was 5.7% (95% confidence interval [CI]: 4.6%-6.9%, 95/1,675), which was significantly higher than that in nonelderly (older than 20 years and younger than 80 years) patients (4.5%, 4.1%-5.0%, 393/8,645). Predictive factors for ESD-associated bleeding differed between nonelderly and elderly patients. On multivariate analysis of predictive factors at the time of treatment, risk factors in elderly patients were hemodialysis (odds ratio: 4.591, 95% CI: 2.056-10.248, P < 0.001) and warfarin use (odds ratio: 4.783, 95% CI: 1.689-13.540, P = 0.003).Discussion:This multicenter study found that the incidence of delayed bleeding after ESD in Japanese patients older than 80 years was high, especially in patients receiving hemodialysis and taking warfarin. Management of ESD to prevent delayed bleeding requires particular care in patients older than 80 years

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「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

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