948 research outputs found
Development and Applications of VSV Vectors Based on Cell Tropism
Viral vectors have been available in various fields such as medical and biological research or gene therapy applications. Targeting vectors pseudotyped with distinct viral envelope proteins that influence cell tropism and transfection efficiency are useful tools not only for examining entry mechanisms or cell tropisms but also for vaccine vector development. Vesicular stomatitis virus (VSV) is an excellent candidate for development as a pseudotype vector. A recombinant VSV lacking its own envelope (G) gene has been used to produce a pseudotype or recombinant VSV possessing the envelope proteins of heterologous viruses. These viruses possess a reporter gene instead of a VSV G gene in their genome, and therefore it is easy to evaluate their infectivity in the study of viral entry, including identification of viral receptors. Furthermore, advantage can be taken of a property of the pseudotype VSV, which is competence for single-round infection, in handling many different viruses that are either difficult to amplify in cultured cells or animals or that require specialized containment facilities. Here we describe procedures for producing pseudotype or recombinant VSVs and a few of the more prominent examples from envelope viruses, such as hepatitis C virus, Japanese encephalitis virus, baculovirus, and hemorrhagic fever viruses
A capsidless ssRNA virus hosted by an unrelated dsRNA virus
Viruses typically encode the capsid that encases their genome, while satellite viruses do not encode a replicase and depend on a helper virus for their replication1. Here, we report interplay between two RNA viruses, yado-nushi virus 1 (YnV1) and yado-kari virus 1 (YkV1), in a phytopathogenic fungus, Rosellinia necatrix2. YkV1 has a close phylogenetic affinity to positive-sense, single-stranded (+)ssRNA viruses such as animal caliciviruses3, while YnV1 has an undivided double-stranded (ds) RNA genome with a resemblance to fungal totiviruses4. Virion transfection and infectious full-length cDNA transformation has shown that YkV1 depends on YnV1 for viability, although it probably encodes functional RNA-dependent RNA polymerase (RdRp). Immunological and molecular analyses have revealed trans-encapsidation of not only YkV1 RNA but also RdRp by the capsid protein of the other virus (YnV1), and enhancement of YnV1 accumulation by YkV1. This study demonstrates interplay in which the capsidless (+)ssRNA virus (YkV1), hijacks the capsid protein of the dsRNA virus (YnV1), and replicates as if it were a dsRNA virus
Facile synthesis of picenes incorporating imide moieties at both edges of the molecule and their application to n-channel field-effect transistors
Picene derivatives incorporating imide moieties along the long-axis direction of the picene core (Cn-PicDIs) were conveniently synthesized through a four-step synthesis. Photochemical cyclization of dinaphthylethenes was used as the key step for constructing the picene skeleton. Field-effect transistor (FET) devices of Cn-PicDIs were fabricated by using ZrO2 as a gate substrate and their FET characteristics were investigated. The FET devices showed normally-off n-channel operation; the averaged electron mobility (μ) was evaluated to be 2(1) × 10−4, 1.0(6) × 10−1 and 1.4(3) × 10−2 cm2 V−1 s−1 for C4-PicDI, C8-PicDI and C12-PicDI, respectively. The maximum μ value as high as 2.0 × 10−1 cm2 V−1 s−1 was observed for C8-PicDI. The electronic spectra of Cn-PicDIs in solution showed the same profiles irrespective of the alkyl chain lengths. In contrast, in thin films, the UV absorption and photoelectron yield spectroscopy (PYS) indicated that the lowest unoccupied molecular orbital (LUMO) level of Cn-PicDIs gradually lowered upon the elongation of the alkyl chains, suggesting that the alkyl chains modify intermolecular interactions between the Cn-PicDI molecules in thin films. The present results provide a new strategy for constructing a high performance n-channel organic semiconductor material by utilizing the electronic features of phenacenes
A novel quadripartite dsRNA virus isolated from a phytopathogenic filamentous fungus, Rosellinia necatrix
AbstractHere we report the biological and molecular attributes of a novel dsRNA virus isolated from Rosellinia necatrix, a filamentous phytopathogenic fungus. The virus, termed Rosellinia necatrix quadrivirus 1 (RnQV1), forms rigid spherical particles approximately 45nm in diameter in infected mycelia. The particles contain 4 dsRNA segments, dsRNA1 to dsRNA4, with a size range of 4.9 to 3.7kbp, each possessing a single large ORF. A comparison of the virus-infected and -cured isogenic fungal strains suggested that RnQV1 infection has no appreciable phenotypic effects. Phylogenetic analysis using the dsRNA3-encoded RdRp sequence revealed that RnQV1 is more distantly related to quadripartite chrysoviruses than to monopartite totiviruses, and is placed in a distinct group from other mycoviruses. No significant sequence similarities were evident between known proteins and RnQV1 structural proteins shown to be encoded by dsRNA2 or dsRNA4. These suggest that RnQV1 is a novel latent virus, belonging to a new family
Synthesis of [7]phenacene incorporating tetradecyl chains in the axis positions and its application in field-effect transistors
Field-effect transistors (FETs) were fabricated using a new type of phenacene molecule, 3,12-ditetradecyl[7]phenacene ((C14H29)2-[7]phenacene), and solid gate dielectrics or an electric double layer (EDL) capacitor with an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (bmim[PF6])). The new molecule, (C14H29)2-[7]phenacene, was efficiently synthesized via the Mallory photoreaction. Its crystal structure and electronic properties were determined, using X-ray diffraction, scanning tunneling microscopy/spectroscopy (STM and STS), absorption spectroscopy, and photoelectron yield spectroscopy, which showed a monoclinic crystal lattice (space group P21 (no. 4)) and an energy gap of ∼3.0 eV. The STM image clearly showed the molecular structure of (C14H29)2-[7]phenacene, as well as the closed molecular stacking, indicative of a strong fastener effect between alkyl chains. The X-ray diffraction pattern of thin films of (C14H29)2-[7]phenacene formed on a SiO2/Si substrate suggested that the molecule stood on the surface with an inclined angle of 30° with respect to the normal axis of the surface. The FET properties were recorded in two-terminal measurement mode, showing p-channel normally-off characteristics. The averaged values of field-effect mobility, μ, were 1.6(3) cm2 V−1 s−1 for a (C14H29)2-[7]phenacene thin-film FET with a SiO2 gate dielectric and 6(4) × 10−1 cm2 V−1 s−1 for a (C14H29)2-[7]phenacene thin-film EDL FET with bmim[PF6]. Thus, higher FET performance was obtained with an FET using a thin film of (C14H29)2-[7]phenacene compared to parent [7]phenacene. This study could pioneer an avenue for the realization of high-performance FETs through the addition of alkyl chains to phenacene molecules
Kissing Aneurysm of the Distal Anterior Cerebral Artery: Preoperative CT Angiography and Surgical Management: A
We describe a patient with mirror-image aneurysms in the bilateral distal anterior cerebral artery (ACA). The larger aneurysm was clearly disclosed with digital subtraction angiography (DSA), but the smaller one could not be definitely identified. The bilateral aneurysms were confirmed with computed tomographic (CT) angiography, which showed the right ACA aneurysm to be hidden behind the left ACA aneurysm, likely buried in the cingulate gyrus. During surgery, the left ACA aneurysm was clipped first. The right ACA aneurysm was exposed by a small subpial resection of the cingulate gyrus, and the right ACA aneurysm, which strongly adhered to the surrounding tissue, was safely dissected. Multiple aneurysms associated with a distal ACA aneurysm are not rare. We conclude that further examination with CT angiography is important when kissing aneurysms are suggested by DSA
High interleukin-6 levels induced by COVID-19 pneumonia correlate with increased circulating follicular helper T cell frequency and strong neutralization antibody response in the acute phase of Omicron breakthrough infection
BackgroundAcute immune responses to coronavirus disease 2019 (COVID-19) are influenced by variants, vaccination, and clinical severity. Thus, the outcome of these responses may differ between vaccinated and unvaccinated patients and those with and without COVID-19-related pneumonia. In this study, these differences during infection with the Omicron variant were investigated.MethodsA total of 67 patients (including 47 vaccinated and 20 unvaccinated patients) who were hospitalized within 5 days after COVID-19 symptom onset were enrolled in this prospective observational study. Serum neutralizing activity was evaluated using a pseudotyped virus assay and serum cytokines and chemokines were measured. Circulating follicular helper T cell (cTfh) frequencies were evaluated using flow cytometry.ResultsTwenty-five patients developed COVID-19 pneumonia on hospitalization. Although the neutralizing activities against wild-type and Delta variants were higher in the vaccinated group, those against the Omicron variant as well as the frequency of developing pneumonia were comparable between the vaccinated and unvaccinated groups. IL-6 and CXCL10 levels were higher in patients with pneumonia than in those without it, regardless of their vaccination status. Neutralizing activity against the Omicron variant were higher in vaccinated patients with pneumonia than in those without it. Moreover, a distinctive correlation between neutralizing activity against Omicron, IL-6 levels, and cTfh proportions was observed only in vaccinated patients.ConclusionsThe present study demonstrates the existence of a characteristic relationship between neutralizing activity against Omicron, IL-6 levels, and cTfh proportions in Omicron breakthrough infection
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