74 research outputs found
Akari Observations of Brown Dwarfs. II CO2 as Probe of Carbon and Oxygen Abundances in Brown Dwarfs
Recent observations with the infrared astronomical satellite AKARI have shown
that the CO2 bands at 4.2 micron in three brown dwarfs are much stronger than
expected from the unified cloudy model (UCM) based on recent solar C & O
abundances. This result has been a puzzle, but we now find that this is simply
an abundance effect: We show that these strong CO2 bands can be explained with
the UCMs based on the classical C & O abundances (log Ac and log Ao), which are
about 0.2 dex larger compared to the recent values. Since three other brown
dwarfs could be well interpreted with the recent solar C & O abundances, we
require at least two model sequences based on the different chemical
compositions to interpret all the AKARI spectra. The reason for this is that
the CO2 band is especially sensitive to C & O abundances, since the CO2
abundance depends approximately on AcAo^2 --- the cube of C & O abundances. For
this reason, even low resolution spectra of very cool dwarfs, especially of CO2
cannot be understood unless a model with proper abundances is applied. For the
same reason, CO2 is an excellent indicator of C & O abundances, and we can now
estimate C & O abundances of brown dwarfs: Three out of six brown dwarfs
observed with AKARI should have high C & O abundances similar to the classical
solar values (e.g. logAc = 8.60 and logAo = 8.92), but the other three may have
low C & O abundances similar to the recent solar values (e.g. logAc = 8.39 and
logAo = 8.69). This result implies that three out of six brown dwarfs are
highly metal rich relative to the Sun if the recent solar C & O abundances are
correct.Comment: 12 pages, 6 figures, To appear in ApJ June 20 issu
TGR5活性化はアナグリプチンによる糖尿病ラットに対する肝線維化抑制効果を増強する
Hyperglycemia and hyperinsulinemia activate the proliferative potential of hepatic stellate cells (HSCs) and promote hepatic fibrosis. Dipeptidyl peptidase-4 (DPP-4) inhibitors, antidiabetic agents, reportedly inhibit the HSC proliferation. Additionally, Takeda G protein-coupled receptor 5 (TGR5) agonists induce the systemic release of glucagon-like peptides from intestinal L cells, which maintains glycemic homeostasis. This study assessed the combined effect of TGR5 agonist and DPP-4 inhibitor on diabetes-based liver fibrosis development. Male diabetic rats received intraperitoneal injection of porcine serum (PS) to induce liver fibrosis, and they were orally administered the following agents: oleanolic acid (OA) as a TGR5 agonist, anagliptin (ANA) as a DPP-4 inhibitor, and a combination of both agents. Treatment with OA or ANA significantly improved glycemic status and attenuated intrahepatic steatosis and lipid peroxidation in diabetic rats. PS-induced liver fibrosis development was also drastically suppressed by treatment with either agent, and the combination of both reciprocally enhanced the antifibrotic effect. Fecal microbiome demonstrated that both agents inhibited the increase in the Firmicutes/Bacteroidetes ratio, an indicator of dysbiosis related to metabolic syndromes. Furthermore, ANA directly inhibited in vitro HSC proliferative and profibrogenic activities. Collectively, TGR5 agonist and DPP-4 inhibitor appears to be a novel strategy against liver fibrosis under diabetic conditions.博士(医学)・甲第766号・令和3年3月15日© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
Late-onset spastic ataxia phenotype in a patient with a homozygous DDHD2 mutation
Autosomal recessive cerebellar ataxias and autosomal recessive hereditary spastic paraplegias (ARHSPs) are clinically and genetically heterogeneous neurological disorders. Herein we describe Japanese siblings with a midlife-onset, slowly progressive type of cerebellar ataxia and spastic paraplegia, without intellectual disability. Using whole exome sequencing, we identified a homozygous missense mutation in DDHD2, whose mutations were recently identified as the cause of early-onset ARHSP with intellectual disability. Brain MRI of the patient showed a thin corpus callosum. Cerebral proton magnetic resonance spectroscopy revealed an abnormal lipid peak in the basal ganglia, which has been reported as the hallmark of DDHD2-related ARHSP (SPG 54). The mutation caused a marked reduction of phospholipase A(1) activity, supporting that this mutation is the cause of SPG54. Our cases indicate that the possibility of SPG54 should also be considered when patients show a combination of adult-onset spastic ataxia and a thin corpus callosum. Magnetic resonance spectroscopy may be helpful in the differential diagnosis of patients with spastic ataxia phenotype.ArticleSCIENTIFIC REPORTS. 4:7132 (2014)journal articl
Exome Sequencing Reveals a Homozygous SYT14 Mutation in Adult-Onset, Autosomal-Recessive Spinocerebellar Ataxia with Psychomotor Retardation
Autosomal-recessive cerebellar ataxias (ARCAs) are clinically and genetically heterogeneous disorders associated with diverse neurological and nonneurological features that occur before the age of 20. Currently, mutations in more than 20 genes have been identified, but approximately half of the ARCA patients remain genetically unresolved. In this report, we describe a Japanese family in which two siblings have slow progression of a type of ARCA with psychomotor retardation. Using whole-exome sequencing combined with homozygosity mapping, we identified a homozygous missense mutation in SYT14, encoding synaptotagmin XIV (SYT14). Expression analysis of the mRNA of SYT14 by a TaqMan assay confirmed that SYT14 mRNA was highly expressed in human fetal and adult brain tissue as well as in the mouse brain (especially in the cerebellum). In an in vitro overexpression system, the mutant SYT14 showed intracellular localization different from that of the wild-type. An immunohistochemical analysis clearly showed that SYT14 is specifically localized to Purkinje cells of the cerebellum in humans and mice. Synaptotagmins are associated with exocytosis of secretory vesicles (including synaptic vesicles), indicating that the alteration of the membrane-trafficking machinery by the SYT14 mutation may represent a distinct pathomechanism associated with human neurodegenerative disorders
Examination of Selective Low-pressure Fine Needle Aspiration Cytology Under Ultrasound Guidance
Cytology by fine-needle cytology is indispensable for diagnosing head and neck tumor, especially for thyroid nodule. There are two methods of fine needle cytology; one of fine-needle aspiration cytology (FNAC and another of fine-needle non-aspiration cytology (FNNAC). These previous procedures has each disadvantage such as the mixing of blood or low yield of cells. We proposed a new technique: selective low-pressure fine needle aspiration cytology (SLOP-FNAC) to overcome the backwards of previous procedures. We used the scoring system by Mair et al. to evaluate smear quality of specimens obtained with FNNAC and SLOP-FNAC. SLOP-FNAC smears exhibited higher scores in amount of cellular material, degree of cellular degeneration and cell yield, and retention of appropriate architecture compared to FNNAC smears. The SLOP-FNAC smears scored significantly higher for amount of cellular material and retention of appropriate architecture evaluated (P = 0.0261 and P = 0.0024, Student’s t-test). SLOP-FNAC may be a useful cell sampling technique that reduces blood contamination while securing a high cell yield with maintaining tissue structure
Progress in Outreach of ERI’s Research Results Using Interactive Rich Contents Display System
We have developed an interactive display system operated by touch panel as one of the best ways to reach out the visitors by showing the outcomes of the Earthquake Research Institute (ERI). In this paper, we report some of the contents and the benefits of the interactive display. Research results are summarized as movies or high resolution graphics which we call “rich-contents”. We provide 65 and 45 inch touch panels connected to PCs which run Vizlmpress envision software developed by SGI, Japan. The rich-contents consist of three parts: 1) Introduction of Earthquakes and Volcanoes, 2) Outline of ERI, and 3) Research Highlights. Part 1 provides an animation of asperity, historical earthquake prints (Namazu-e) and disaster pictures, photos from "The Great Earthquake in Japan 1891" taken by J. Milne and W.K. Burton, and a high resolution map of the world seismicity. Part 2 includes a general description and history of ERI, photos of researchers, and ERI booklets such as brochure, annual reports or newsletters. Part 3 presents videos of observation sceneries from the top of the active volcanoes or from the cruise for settling ocean bottom seismometers. Computer simulations of strong ground motions, Tsunamis, mantle convection, and seismic shaking of builidngs are also included. One of the most enjoyable contents is the 3-dimensional seismicity map around Japan, from which you can rotate Japan and get to know how the oceanic plates subduct beneath Japan. This system was demonstrated at the exhibition booths of the Japan Geoscience Union mettings in 2007 and 2008, and Cities on Volcanoes 5 conference in 2007, and got the attention of visitors including high school students. The key factors of this captivation, in addition to the attractive and dynamic research results themselves, may be brought from 1) the quick response of the touch panel as well as the smooth zoom-in and zoom-out, and 2) a close distance between the audience and the presenter so that the presenter can be viewed as a part of the screen
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