123 research outputs found

    An interpretation of historical records of aurorae and meteors in Chinaduring the 11th and 12th centuries A.D.: Possible indications ofaccretion of interstellar medium?

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    More than 5000 meteors were recorded in ancient Chinese chronicles. The frequency of meteor sighting shows an anomalous increase during the 11th century A. D. This seems to be consistent with the inference that the solar system encountered a small molecular cloud, although KEIMATSU et al. (J. Geomagn. Geoelectr., 20,45,1968) suggested that the geomagnetic dipole axis could have been inclined towards China around the 11th century based on historical records of aurorae and sunspots

    Terrestrial ages of the Antarctic meteorites measured by thermoluminescence of the fusion crust: II

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    The acquired doses of Antarctic meteorites for dating of terrestrial ages were measured by the thermoluminescence (TL) intensity of fusion crust. It is now clearer that there is a significant correlation between the acquired dose and terrestrial age, which was previously measured by cosmogenic radionuclide abundance. Also, the ^Cl method by accelerator mass spectrometry seems to provide a large terrestrial age occasionally

    Terrestrial ages of Antarctic meteorites measured by thermoluminescence of the fusion crust

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    The acquired doses of 14 Antarctic meteorites were measured using the thermoluminescent (TL) intensity of the fusion crust. It was found that there is a good correlation between the acquired TL doses and the terrestrial ages, which were previously measured by the cosmogenic radionuclide abundance

    PIXE analysis of magnetic spherules in Paleozoic-Mesozoic bedded chert

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    Particle Induced X-ray Emission (PIXE) was applied to the elemental characterization of magnetic microspherules collected from the Paleozoic and Mesozoic bedded chert in Southwest Japan. Comparison of the titanium and chromium contents of the spherules with the magnetic components of meteorites and volcanic ash showed that this technique offers promising potential as a new method for distinguishing between spherules of terrestrial and extraterrestrial origin

    指尖部切断に対する動脈島状皮弁をもちいた再建術後のPIP関節屈曲拘縮の予見因子の検討

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    PURPOSE: To identify independent predictors of postoperative proximal interphalangeal (PIP) joint contracture after direct-flow homodigital island flap transfer. METHODS: Forty-four fingertip amputations in 39 patients treated with oblique triangular flaps were evaluated at a minimum of 1 year after surgery. Five variables were examined: patient age, injured finger, mechanism of injury, flap advancement distance, and time required for wound healing. Univariate and multivariate linear regression analyses were performed to identify the extent to which these variables affected the flexion contracture of the PIP joint. RESULTS: The average reduction in the passive extension angle of the PIP joint was 16° at final follow-up. Univariate analysis indicated significant correlations of PIP joint flexion contracture with age, injured finger, and time for wound healing, but no significant correlation with the distance the flap was advanced. Multivariate analysis indicated that the age and duration of wound healing were independent predictors of the flexion contracture of the PIP joint. CONCLUSIONS: Elderly people and cases with delayed wound healing are at risk for postoperative PIP joint contracture after homodigital flap transfer. Intervention with early hand therapy and orthotics may be useful in elderly patients with delayed wound healing.博士(医学)・乙第1377号・平成28年7月8日Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved

    V3 Tip-Dependent Species Specificity of HIV-1 Env

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    Molecular interactions of the variable envelope gp120 subunit of HIV-1 with two cellular receptors are the first step of viral infection, thereby playing pivotal roles in determining viral infectivity and cell tropism. However, the underlying regulatory mechanisms for interactions under gp120 spontaneous variations largely remain unknown. Here, we show an allosteric mechanism in which a single gp120 mutation remotely controls the ternary interactions between gp120 and its receptors for the switch of viral cell tropism. Virological analyses showed that a G310R substitution at the tip of the gp120 V3 loop selectively abolished the viral replication ability in human cells, despite evoking enhancement of viral replication in macaque cells. Molecular dynamics (MD) simulations predicted that the G310R substitution at a site away from the CD4 interaction site selectively impeded the binding ability of gp120 to human CD4. Consistently, virions with the G310R substitution exhibited a reduced binding ability to human lymphocyte cells. Furthermore, the G310R substitution influenced the gp120-CCR5 interaction in a CCR5-type dependent manner as assessed by MD simulations and an infectivity assay using exogenously expressed CCR5s. Interestingly, an I198M mutation in human CCR5 restored the infectivity of the G310R virus in human cells. Finally, MD simulation predicted amino acid interplays that physically connect the V3 loop and gp120 elements for the CD4 and CCR5 interactions. Collectively, these results suggest that the V3 loop tip is a cis-allosteric regulator that remotely controls intra- and intermolecular interactions of HIV-1 gp120 for balancing ternary interactions with CD4 and CCR5

    Virological characterization of HIV-1 CA-NTD mutants constructed in a virus-lineage reflected manner

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    Capsid (CA) protein is a major virion-constituent of all retroviruses including human immunodeficiency virus type 1 (HIV-1), and is essential for early and late phases in viral replication cycle through interaction with numerous cellular factors. In particular, N-terminal domain (NTD) of HIV-1 CA has been frequently and well reported to bind to various host cell proteins that considerably affect viral replication potential. In this study, in order to better define biological bases of the CA-NTD for HIV-1 replication, we performed an extensive mutational analysis in an unprecedented manner. By aligning CA-NTD sequences derived from representative infectious molecular clones of HIV-1, HIV-2, and simian immunodeficiency virus isolated from the rhesus macaque (SIVmac), a number of amino acids specific to HIV-1 were selected, and were replaced with those from SIVmac at the corresponding sites. Mutant viruses thus generated were then examined for multi-cycle infectivity, single-cycle infectivity, and ability to produce progeny virions. While some CA-NTD mutations affected viral replication ability to varying degrees, those in helix 7 abolished viral growth potential without exception. These results highlight functional importance of non-conserved amino acids in helix 7, and give new insights into functionality of HIV-1 CA-NTD

    Virological characterization of HIV-1 CA-NTD mutants constructed in a virus-lineage reflected manner

    Get PDF
    Capsid (CA) protein is a major virion-constituent of all retroviruses including human immunodeficiency virus type 1 (HIV-1), and is essential for early and late phases in viral replication cycle through interaction with numerous cellular factors. In particular, N-terminal domain (NTD) of HIV-1 CA has been frequently and well reported to bind to various host cell proteins that considerably affect viral replication potential. In this study, in order to better define biological bases of the CA-NTD for HIV-1 replication, we performed an extensive mutational analysis in an unprecedented manner. By aligning CA-NTD sequences derived from representative infectious molecular clones of HIV-1, HIV-2, and simian immunodeficiency virus isolated from the rhesus macaque (SIVmac), a number of amino acids specific to HIV-1 were selected, and were replaced with those from SIVmac at the corresponding sites. Mutant viruses thus generated were then examined for multi-cycle infectivity, single-cycle infectivity, and ability to produce progeny virions. While some CA-NTD mutations affected viral replication ability to varying degrees, those in helix 7 abolished viral growth potential without exception. These results highlight functional importance of non-conserved amino acids in helix 7, and give new insights into functionality of HIV-1 CA-NTD

    Pachychoroid neovasculopathy and age-related macular degeneration.

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    Pachychoroid neovasculopathy is a recently proposed clinical entity of choroidal neovascularization (CNV). As it often masquerades as neovascular age-related macular degeneration (AMD), it is currently controversial whether pachychoroid neovasculopathy should be distinguished from neovascular AMD. This is because its characteristics have yet to be well described. To estimate the relative prevalence of pachychoroid neovasculopathy in comparison with neovascular AMD and to investigate the phenotypic/genetic differences of the two diseases, we evaluated 200 consecutive Japanese patients who agreed to participate in the genetic study and diagnosed with pachychoroid neovasculopathy or neovascular AMD. Pachychoroid neovasculopathy was observed in 39 individuals (19. 5%), which corresponds to one fourth of neovascular AMD. Patients with pachychoroid neovasculopathy were significantly younger (p = 5. 1 × 10[−5]) and showed a greater subfoveal choroidal thickness (p = 3. 4 × 10[−14]). Their genetic susceptibility to AMD was significantly lower than that of neovascular AMD; ARMS2 rs10490924 (p = 0. 029), CFH rs800292 (p = 0. 013) and genetic risk score calculated from 11 AMD susceptibility genes (p = 3.8 × 10[−3]). Current results implicate that the etiologies of the two conditions must be different. Thus, it will be necessary to distinguish these two conditions in future studie
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