1,589 research outputs found

    The complete chloroplast genome sequence of Abies nephrolepis (Pinaceae: Abietoideae)

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    AbstractThe plant chloroplast (cp) genome has maintained a relatively conserved structure and gene content throughout evolution. Cp genome sequences have been used widely for resolving evolutionary and phylogenetic issues at various taxonomic levels of plants. Here, we report the complete cp genome of Abies nephrolepis. The A. nephrolepis cp genome is 121,336 base pairs (bp) in length including a pair of short inverted repeat regions (IRa and IRb) of 139 bp each separated by a small single copy (SSC) region of 54,323 bp (SSC) and a large single copy region of 66,735 bp (LSC). It contains 114 genes, 68 of which are protein coding genes, 35 tRNA and four rRNA genes, six open reading frames, and one pseudogene. Seventeen repeat units and 64 simple sequence repeats (SSR) have been detected in A. nephrolepis cp genome. Large IR sequences locate in 42-kb inversion points (1186 bp). The A. nephrolepis cp genome is identical to Abies koreana’s which is closely related to taxa. Pairwise comparison between two cp genomes revealed 140 polymorphic sites in each. Complete cp genome sequence of A. nephrolepis has a significant potential to provide information on the evolutionary pattern of Abietoideae and valuable data for development of DNA markers for easy identification and classification

    Inhibition of HIV replication by amino-sugar derivatives

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    AbstractThe plant alkaloids castanospermine, dihydroxymethyldihydroxypyrrolidine and deoxynojirimycin have recently been shown to have potential anti-HIV activity [(1987) Proc. Natl. Acad. Sci. USA 84, 8120–8124; (1987) Nature 330, 74–77; (1987) Lancet i, 1025–1026]. They are thought to act by inhibiting α-glucosidase I, an enzyme involved in the processing of N-linked oligosaccharides on glycoproteins. We report here the relative efficacy of a spectrum of amino-sugar derivatives as inhibition of HIV cytopathicity. Several α-glucosidase inhibitors and α-fucosidase inhibitors were found to be active at concentrations which were non-cytotoxic

    Effects of α-Phenyl-N-tert-Butyl Nitrone (PBN) on Brain Cell Membrane Function and Energy Metabolism during Transient Global Cerebral Hypoxia-Ischemia and Reoxygenation-Reperfusion in Newborn Piglets

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    We sought to know whether a free radical spin trap agent, α-phenyl-N-tert-butyl nitrone (PBN) influences brain cell membrane function and energy metabolism during and after transient global hypoxia-ischemia (HI) in the newborn piglets. Cerebral HI was induced by temporary complete occlusion of bilateral common carotid arteries and simultaneous breathing with 8% oxygen for 30 min, followed by release of carotid occlusion and normoxic ventilation for 1 hr (reoxygenation-reperfusion, RR). PBN (100 mg/kg) or vehicle was administered intravenously just before the induction of HI or RR. Brain cortex was harvested for the biochemical analyses at the end of HI or RR. The level of conjugated dienes significantly increased and the activity of Na+, K+-ATPase significantly decreased during HI, and they did not recover during RR. The levels of ATP and phosphocreatine (PCr) significantly decreased during HI, and recovered during RR. PBN significantly decreased the level of conjugated dienes both during HI and RR, but did not influence the activity of Na+, K+-ATPase and the levels of ATP and PCr. We demonstrated that PBN effectively reduced brain cell membrane lipid peroxidation, but did not reverse ongoing brain cell membrane dysfunction nor did restore brain cellular energy depletion, in our piglet model of global hypoxic-ischemic brain injury

    Spintronics: Fundamentals and applications

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    Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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