123 research outputs found

    Controlling strength and toughness of multilayer films: A new multiscalar approach

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    Multiscalar films are produced in order to combine both toughness and strength into a multilayer film. These structures incorporate both a strengthening phase and a toughening phase in a compositionally modulated microcomposite. The mechanical properties and microstructure for thick (∼50 μm) Mo/W multiscalar films have been characterized. A detailed microstructural analysis (including transmission electron microscopy, scanning electron microscopy, and x‐ray techniques) of Mo/W multiscalar films has shown that large single‐crystal columns of Mo interspersed with epitaxial layers of W extend for the entire film thickness. The microstructure is a zone‐II‐type microstructure, yet the temperatures during deposition are well below the lower limit (0.3 T/Tm) previously reported for such microstructures. Hardness and tensile tests have shown that a multiscalar approach is capable of tailoring a desired strength and toughness into a multilayered film.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70675/2/JAPIAU-74-2-1015-1.pd

    Transmission in NFS/N mice of the heritable spongiform encephalopathy associated with the gray tremor mutation.

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    It has been shown that the autosomal recessive mutation, gray tremor (gt) was associated in the homozygous state (gt/gt) with a rapidly fatal spongiform encephalopathy. Heterozygotes (+/gt) developed mild asymptomatic spongiform brain lesions as did recipient inbred mice inoculated with gt/gt brain homogenates, some of whom also showed behavioral abnormalities [Sidman, R. L., Kinney, H. C. & Sweet, H. O. (1985) Proc. Natl. Acad. Sci. USA 82, 253-257]. In these studies, inbred NFS/N mice inoculated intracerebrally at birth or as adults with gt/gt or first passage gt brain homogenates developed a progressive disease characterized by tremor, ataxia, and spasticity. The symptoms were milder and more slowly progressive than in the gt/gt homozygote, in the paralytic syndrome that followed neonatal inoculation of NFS/N mice with a wild murine leukemia virus (Cas-Br-M MuLV), or in the rapidly progressive ataxia and terminal bradykinesia that followed scrapie inoculation of NFS/N mice. The noninflammatory spongiform encephalopathy in affected NFS/N mice resembled that observed in gt/gt homozygotes, +/gt heterozygotes, and asymptomatic recipient inbred mice inoculated with gt/gt brain homogenates. Neither infectious MuLV nor MuLV proteins were detected in gt/gt brain homogenates or in affected recipient mouse brains. Scrapie-associated fibrils, readily identifiable in subcellular fractions of brains from scrapie-inoculated NFS/N mice, were not detected in similar brain fractions from NFS/N mice inoculated with gt brain homogenates. These results confirm and extend the suggestion that gt spongiform encephalopathy has both heritable and transmissible properties. Moreover, the transmissible agent of gt disease differs from both Cas-Br-M MuLV and scrapie in its disease-inducing properties in NFS/N mice. The capacity of NFS/N mice to express transmitted gt encephalopathy as clinical disease, to rapidly express Cas-Br-M MuLV spongiform encephalomyelopathy, and to develop mouse-adapted scrapie after a very short incubation time suggest a distinct sensitivity of NFS/N mice to transmissible spongiform encephalopathy

    Vaccine protection against simian immunodeficiency virus in monkeys using recombinant gamma-2 herpesvirus

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    Recombinant strains of replication-competent rhesus monkey rhadinovirus (RRV) were constructed in which strong promoter/enhancer elements were used to drive expression of simian immunodeficiency virus (SIV) Env or Gag or a Rev-Tat-Nef fusion protein. Cultured rhesus monkey fibroblasts infected with each recombinant strain were shown to express the expected protein. Three RRV-negative and two RRV-positive rhesus monkeys were inoculated intravenously with a mixture of these three recombinant RRVs. Expression of SIV Gag was readily detected in lymph node biopsy specimens taken at 3 weeks postimmunization. Impressive anti-SIV cellular immune responses were elicited on the basis of major histocompatibility complex (MHC) tetramer staining and gamma interferon enzyme-linked immunospot (ELISPOT) assays. Responses were much greater in magnitude in the monkeys that were initially RRV negative but were still readily detected in the two monkeys that were naturally infected with RRV at the time of immunization. By 3 weeks postimmunization, responses measured by MHC tetramer staining in the two Mamu-A*01(+) RRV-negative monkeys reached 9.3% and 13.1% of all CD8(+) T cells in peripheral blood to the Gag CM9 epitope and 2.3% and 7.3% of all CD8(+) T cells in peripheral blood to the Tat SL8 epitope. Virus-specific CD8(+) T cell responses persisted at high levels up to the time of challenge at 18 weeks postimmunization, and responding cells maintained an effector memory phenotype. Despite the ability of the RRVenv recombinant to express high levels of Env in cultured cells, and despite the appearance of strong anti-RRV antibody responses in immunized monkeys, anti-Env antibody responses were below our ability to detect them. Immunized monkeys, together with three unimmunized controls, were challenged intravenously with 10 monkey infectious doses of SIVmac239. All five immunized monkeys and all three controls became infected with SIV, but peak viral loads were 1.2 to 3.0 log(10) units lower and chronic-phase viral loads were 1.0 to 3.0 log(10) units lower in immunized animals than the geometric mean of unimmunized controls. These differences were statistically significant. Anti-Env antibody responses following challenge indicated an anamnestic response in the vaccinated monkeys. These findings further demonstrate the potential of recombinant herpesviruses as preventive vaccines for AIDS. We hypothesize that this live, replication-competent, persistent herpesvirus vector could match, or come close to matching, live attenuated strains of SIV in the degree of protection if the difficulty with elicitation of anti-Env antibody responses can be overcome

    Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120

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    BACKGROUND: Cellulose acetate phthalate (CAP), a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1) and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1) and 2 (HSV-2) and the major nonviral sexually transmitted disease (STD) pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. METHODS: Enzyme-linked immunoassays and flow cytometry were used to demonstrate CAP binding to HIV-1 and to define the binding site on the virus envelope. RESULTS: 1) CAP binds to HIV-1 virus particles and to the envelope glycoprotein gp120; 2) this leads to blockade of the gp120 V3 loop and other gp120 sites resulting in diminished reactivity with HIV-1 coreceptors CXCR4 and CCR5; 3) CAP binding to HIV-1 virions impairs their infectivity; 4) these findings apply to both HIV-1 IIIB, an X4 virus, and HIV-1 BaL, an R5 virus. CONCLUSIONS: These results provide support for consideration of CAP as a topical microbicide of choice for prevention of STDs, including HIV-1 infection

    TRPA1- FGFR2 binding event is a regulatory oncogenic driver modulated by miRNA-142-3p

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    YesRecent evidence suggests that the ion channel TRPA1 is implicated in lung adenocarcinoma (LUAD) where its role and mechanism of action remain unknown. We have previously established that the membrane receptor FGFR2 drives LUAD progression through aberrant protein-protein interactions mediated via its C-terminal proline rich motif. Here, we report that the N-terminal ankyrin repeats of TRPA1 directly bind to the C-terminal proline rich motif of FGFR2 inducing the constitutive activation of the receptor, thereby prompting LUAD progression and metastasis. Furthermore, we show that upon metastasis to the brain, TRPA1 gets depleted, an effect triggered by the transfer of TRPA1-targeting exosomal microRNA (miRNA-142-3p) from brain astrocytes to cancer cells. This downregulation, in turn, inhibits TRPA1-mediated activation of FGFR2 hindering the metastatic process. Our study reveals a direct binding event and characterizes the role of TRPA1 ankyrin repeats in regulating FGFR2-driven oncogenic process; a mechanism that is hindered by miRNA-142-3p.Faculty of Biological Sciences at the University of Leeds, Wellcome Trust Seed Award, Royal Society Research Grant RG150100, MR/K021303/1, Swedish Research Council (2014-3801) and the Medical Faculty at Lund University

    Cytomegalovirus-based vaccine expressing Ebola virus glycoprotein protects nonhuman primates from Ebola virus infection.

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    Ebolaviruses pose significant public health problems due to their high lethality, unpredictable emergence, and localization to the poorest areas of the world. In addition to implementation of standard public health control procedures, a number of experimental human vaccines are being explored as a further means for outbreak control. Recombinant cytomegalovirus (CMV)-based vectors are a novel vaccine platform that have been shown to induce substantial levels of durable, but primarily T-cell-biased responses against the encoded heterologous target antigen. Herein, we demonstrate the ability of rhesus CMV (RhCMV) expressing Ebola virus (EBOV) glycoprotein (GP) to provide protective immunity to rhesus macaques against lethal EBOV challenge. Surprisingly, vaccination was associated with high levels of GP-specific antibodies, but with no detectable GP-directed cellular immunity

    Author Correction: Federated learning enables big data for rare cancer boundary detection.

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    Remdesivir Inhibits SARS-CoV-2 in Human Lung Cells and Chimeric SARS-CoV Expressing the SARS-CoV-2 RNA Polymerase in Mice

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the novel viral disease COVID-19. With no approved therapies, this pandemic illustrates the urgent need for broad-spectrum antiviral countermeasures against SARS-CoV-2 and future emerging CoVs. We report that remdesivir (RDV) potently inhibits SARS-CoV-2 replication in human lung cells and primary human airway epithelial cultures (EC50 = 0.01 μM). Weaker activity is observed in Vero E6 cells (EC50 = 1.65 μM) because of their low capacity to metabolize RDV. To rapidly evaluate in vivo efficacy, we engineered a chimeric SARS-CoV encoding the viral target of RDV, the RNA-dependent RNA polymerase of SARS-CoV-2. In mice infected with the chimeric virus, therapeutic RDV administration diminishes lung viral load and improves pulmonary function compared with vehicle-treated animals. These data demonstrate that RDV is potently active against SARS-CoV-2 in vitro and in vivo, supporting its further clinical testing for treatment of COVID-19
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