117 research outputs found

    Systematic Design of Antireflection Coating for Semi-infinite One-dimensional Photonic Crystals Using Bloch Wave Expansion

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    We present a systematic method for designing a perfect antireflection coating (ARC) for a semi-infinite one-dimensional (1D) photonic crystal (PC) with an arbitrary unit cell. We use Bloch wave expansion and time reversal symmetry, which leads exactly to analytic formulas of structural parameters for the ARC and renormalized Fresnel coefficients of the PC. Surface immittance (admittance and impedance) matching plays an essential role in designing the ARC of 1D PC's, which is shown together with a practical example.Comment: This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physic

    Frequent Loss of Genome Gap Region in 4p16.3 Subtelomere in Early-Onset Type 2 Diabetes Mellitus

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    A small portion of Type 2 diabetes mellitus (T2DM) is familial, but the majority occurs as sporadic disease. Although causative genes are found in some rare forms, the genetic basis for sporadic T2DM is largely unknown. We searched for a copy number abnormality in 100 early-onset Japanese T2DM patients (onset age <35 years) by whole-genome screening with a copy number variation BeadChip. Within the 1.3-Mb subtelomeric region on chromosome 4p16.3, we found copy number losses in early-onset T2DM (13 of 100 T2DM versus one of 100 controls). This region surrounds a genome gap, which is rich in multiple low copy repeats. Subsequent region-targeted high-density custom-made oligonucleotide microarray experiments verified the copy number losses and delineated structural changes in the 1.3-Mb region. The results suggested that copy number losses of the genes in the deleted region around the genome gap in 4p16.3 may play significant roles in the etiology of T2DM

    Risk assessment for hepatitis E virus infection from domestic pigs introduced into an experimental animal facility in a medical school

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    Hepatitis E virus (HEV) is known to cause zoonotic infections from pigs, wild boars and deer. Domestic pigs have been used as an experimental animal model in medical research and training; however, the risks of HEV infection from pigs during animal experiments are largely unknown. Here, we retrospectively investigated the seroprevalence and detection rates of viral RNA in 73 domestic pigs (average 34.5 kg) introduced into an animal experimental facility in a medical school during 2012-2016. We detected anti-HEV immunoglobulin G antibodies in 24 of 73 plasma samples (32.9%), though none of the samples were positive for viral RNA. Plasma samples of 18 pigs were sequentially monitored and were classified into four patterns: sustained positive (5 pigs), sustained negative (5 pigs), conversion to positive (6 pigs) and conversion to negative (2 pigs). HEV genomes were detected in 2 of 4 liver samples from pigs that were transported from the same farm during 2016-2017. Two viral sequences of the overlapping open reading frame (ORF) 2/3 region (97 bp) were identical and phylogenetically fell into genotype 3. A 459-bp length of the ORF2 region of an amplified fragment from a pig transported in 2017 was clustered with the wbJYG1 isolate (subgenotype 3b) with 91.5% (420/459 bp) nucleotide identity. Based on our results, we suggest that domestic pigs introduced into animal facilities carry a potential risk of HEV infection to researchers, trainees and facility staff. Continuous surveillance and precautions are important to prevent HEV infection in animal facilities

    Transgenic mice overexpressing SREBP-1a under the control of the PEPCK promoter exhibit insulin resistance, but not diabetes

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    AbstractSterol regulatory element-binding protein-1 (SREBP-1) is a transcription factor which regulates genes involved in the synthesis of fatty acids and triglycerides. The overexpression of nuclear SREBP-1a in transgenic mice under the control of the PEPCK promoter (TgSREBP-1a) caused a massively enlarged fatty liver and disappearance of peripheral white adipose tissue. In the current study, we estimated the impact of this lipid transcription factor on plasma glucose/insulin metabolism in vivo. TgSREBP-1a exhibited mild peripheral insulin resistance as evidenced by hyperinsulinemia both at fasting and after intravenous glucose loading, and retarded glucose reduction after insulin injection due to decreased plasma leptin levels. Intriguingly, hyperinsulinemia in TgSREBP-1a mice was markedly exacerbated in a fed state and sustained after intravenous glucose loading, and paradoxically decreased after the portal injection of glucose. TgSREBP-1a mice consistently showed very small plasma glucose increases after portal glucose loading because of a large capacity for hepatic glucose uptake. These data suggested that hepatic insulin resistance emerges postprandially. In addition, pancreatic islets from TgSREBP-1a were enlarged. These data demonstrate that SREBP-1a activation in the liver has a strong impact on plasma insulin levels, implicating the potential role of SREBPs in hepatic insulin metabolism relating to insulin resistance

    Differentiation of Donor-Derived Cells into Microglia after Umbilical Cord Blood Stem Cell Transplantation

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    Recent studies have indicated that microglia originate from immature progenitors in the yolk sac. After birth, microglial populations are maintained under normal conditions via self-renewal without the need to recruit monocyte-derived microglial precursors. Peripheral cell invasion of the brain parenchyma can only occur with disruption of the blood-brain barrier. Here, we report an autopsy case of an umbilical cord blood transplant recipient in whom cells derived from the donor blood differentiated into ramified microglia in the recipient brain parenchyma. Although the blood-brain barrier and glia limitans seemed to prevent invasion of these donor-derived cells, most of the invading donor-derived ramified cells were maintained in the cerebral cortex. This result suggests that invasion of donor-derived cells occurs through the pial membrane. Copyright © 2015 by the American Association of Neuropathologists, Inc

    Immittance Matching for Multi-dimensional Open-system Photonic Crystals

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    An electromagnetic (EM) Bloch wave propagating in a photonic crystal (PC) is characterized by the immittance (impedance and admittance) of the wave. The immittance is used to investigate transmission and reflection at a surface or an interface of the PC. In particular, the general properties of immittance are useful for clarifying the wave propagation characteristics. We give a general proof that the immittance of EM Bloch waves on a plane in infinite one- and two-dimensional (2D) PCs is real when the plane is a reflection plane of the PC and the Bloch wavevector is perpendicular to the plane. We also show that the pure-real feature of immittance on a reflection plane for an infinite three-dimensional PC is good approximation based on the numerical calculations. The analytical proof indicates that the method used for immittance matching is extremely simplified since only the real part of the immittance function is needed for analysis without numerical verification. As an application of the proof, we describe a method based on immittance matching for qualitatively evaluating the reflection at the surface of a semi-infinite 2D PC, at the interface between a semi-infinite slab waveguide (WG) and a semi-infinite 2D PC line-defect WG, and at the interface between a semi-infinite channel WG and a semi-infinite 2D PC slab line-defect WG.Comment: 8 pages, 6 figure

    Characterization of a Novel Bat Adenovirus Isolated from Straw-Colored Fruit Bat (Eidolon helvum).

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    Bats are important reservoirs for emerging zoonotic viruses. For extensive surveys of potential pathogens in straw-colored fruit bats (Eidolon helvum) in Zambia, a total of 107 spleen samples of E. helvum in 2006 were inoculated onto Vero E6 cells. The cell culture inoculated with one of the samples (ZFB06-106) exhibited remarkable cytopathic changes. Based on the ultrastructural property in negative staining and cross-reactivity in immunofluorescence assays, the virus was suspected to be an adenovirus, and tentatively named E. helvum adenovirus 06-106 (EhAdV 06-106). Analysis of the full-length genome of 30,134 bp, determined by next-generation sequencing, showed the presence of 28 open reading frames. Phylogenetic analyses confirmed that EhAdV 06-106 represented a novel bat adenovirus species in the genus Mastadenovirus. The virus shared similar characteristics of low G + C contents with recently isolated members of species Bat mastadenoviruses E, F and G, from which EhAdV 06-106 diverged by more than 15% based on the distance matrix analysis of DNA polymerase amino acid sequences. According to the taxonomic criteria, we propose the tentative new species name "Bat mastadenovirus H". Because EhAdV 06-106 exhibited a wide in vitro cell tropism, the virus might have a potential risk as an emerging virus through cross-species transmission

    Physical inactivity is associated with decreased growth differentiation factor 11 in chronic obstructive pulmonary disease

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    Rie Tanaka,1 Hisatoshi Sugiura,1 Mitsuhiro Yamada,1 Tomohiro Ichikawa,1 Akira Koarai,1 Naoya Fujino,1 Satoru Yanagisawa,1 Katsuhiro Onodera,1 Tadahisa Numakura,1 Kei Sato,1 Yorihiko Kyogoku,1 Hirohito Sano,1 Shun Yamanaka,1 Tatsuma Okazaki,1 Tsutomu Tamada,1 Motohiko Miura,2 Tsuneyuki Takahashi,3 Masakazu Ichinose1 1Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan; 2Department of Respiratory Medicine, Tohoku Rosai Hospital, Aoba-ku, Sendai, Japan; 3Department of Internal Medicine, Tohoku Medical and Pharmaceutical University Wakabayashi Hospital, Wakabayashi-ku, Sendai, Japan Background: Growth differentiation factor 11 (GDF11) is reported to possess anti-aging and rejuvenating effects, including muscle regeneration and to be highly expressed in skeletal muscle. Recently, we demonstrated that the levels of plasma GDF11 were decreased in COPD. However, the effect of decreased circulating GDF11 in the pathophysiology of COPD remains unknown. The aim of this study is to investigate the association between the plasma GDF11 levels and various clinical parameters in patients with COPD. Patients and methods: Eighteen ex-smokers as control subjects and 70 COPD patients participated in the current study. We measured the levels of plasma GDF11 using immunoblotting, lung function, physical activity using a triaxial accelerometer, quadriceps strength, exercise capacity, and systemic inflammatory markers. We investigated the association between the levels of plasma GDF11 and these clinical parameters. Results: The levels of plasma GDF11 in the COPD patients had significant positive correlations with the data of lung function. Furthermore, the levels of plasma GDF11 were significantly correlated with the physical activity, quadriceps strength, and exercise capacity. Moreover, the levels of plasma GDF11 were significantly correlated with the data of inflammatory markers. Although various factors were related to GDF11, the multiple regression analysis showed that physical activity was significantly associated with the levels of plasma GDF11. Conclusion: Physical inactivity was significantly related to the decreased GDF11 levels in COPD, which might be useful for understanding the pathogenesis of COPD. Clarifying the relationships between the physical inactivity and GDF11 may reveal a potentially attractive therapeutic approach in COPD via increasing the plasma levels of GDF11. Keywords: physical activity, muscle strength, rejuvenating factor, COP
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