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    Autoionization of Homogeneous Nickel(II) Diphosphane Hydrogenation Catalysts. An NMR Study and Crystal Structures of [Ni(<i>o</i>-MeO-dppe)I<sub>2</sub>] and [Ni(<i>o</i>-MeO-dppe)<sub>2</sub>](PF<sub>6</sub>)<sub>2</sub>

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    The synthesis of a number of nickel(II) complexes containing the didentate phosphane ligand 1,2-bis(di(o-methoxyphenyl)phosphino)ethane (o-MeO-dppe) is reported. Two types of complexes have been synthesized, i.e., the mono(chelate) complex (1) of the general formula [Ni(o-MeO-dppe)X2] (where X = Cl, Br or I) and the bis(chelate) complex (2) of the general formula [Ni(o-MeO-dppe)2]Y2 (where Y = PF6 or trifluoroacetate (TFA)). These complexes have been characterized using electronic absorption and NMR spectroscopy. The structures of the mono(chelate) complex [Ni(o-MeO-dppe)I2] (1c) and of the bis(chelate) complex [Ni(o-MeO-dppe)2](PF6)2 (2e) have been determined by X-ray crystallography. [Ni(o-MeO-dppe)I2] crystallizes in the monoclinic space group P21/c with Z = 4, a = 12.1309(1) Å, b = 16.5759(3) Å, c = 17.6474(2) Å, β = 119.3250(10)°. [Ni(o-MeO-dppe)2](PF6)2 crystallizes in the monoclinic space group C2/c with Z = 4, a = 22.5326(3) Å, b = 13.6794(2) Å, c = 21.7134(3) Å, β = 107.1745(7)°. In both structures the nickel ion is in a square-planar geometry with a NiP2I2 and NiP4 chromophore, respectively. Using 1H and 31P{1H} NMR spectroscopy the behavior of the complexes in various solvents has been studied. It appears that in solution these nickel complexes are involved in an autoionization equilibrium:  2[Ni(o-MeO-dppe)X2] ⇋ [Ni(o-MeO-dppe)2]2+ + [“NiX4”]2-. The ionized complex (3) consists of a cationic unit in which a nickel atom is surrounded by two didentate phosphane ligands, and an anionic unit that stoichiometrically consists of a nickel atom and four anions. The position of the autoionization equilibrium is highly dependent on the anion and the solvent used. In a polar solvent in combination with weakly coordinating anions only the ionized complex is observed, whereas in an apolar solvent in combination with coordinating anions only the mono(chelate) complex occurs. A comparison of the behavior of o-MeO-dppe with its unsubstituted analogue dppe in combination with nickel(II) acetate using 31P{1H} NMR spectroscopy shows that the latter is more readily oxidized

    The first fatal intoxication with 3-MeO-PCP in the UK and a review of the literature

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    The phencyclidine derivative 3-Methoxyphencyclidine (3-MeO-PCP) is a potent dissociative hallucinogen. Sought for recreational use as a novel psychoactive substance, it can also induce acute psychological agitation and pathophysiological cardiorespiratory effects. Due to the harms associated with its use, 3-MeO-PCP was added to the ‘Green List’ of materials covered by the 1971 Convention on Psychotropic Substances as a Schedule II substance by the United Nations Commission on Narcotic Drugs in April 2021. There have been 15 previous reports of fatal intoxications following 3-MeO-PCP use, but only one was attributable to 3-MeO-PCP intoxication alone. In this report we detail the first fatality due to 3-MeO-PCP intoxication to be reported in the UK, along with a review of the surrounding literature. Whilst the blood concentrations associated with 3-MeO-PCP toxicity and fatality remain unclear, by providing details of sample collection and storage conditions this case will aid in future interpretations. Furthermore, this case suggests that 3-MeO-PCP toxicity may be exacerbated by exercise. Users of 3-MeO-PCP should be cautioned against its use as a ‘club drug’ or in a similar setting where elevations in heart rate, body temperature and blood pressure may occur.</p

    The first fatal intoxication with 3-MeO-PCP in the UK and a review of the literature

    No full text
    The phencyclidine derivative 3-Methoxyphencyclidine (3-MeO-PCP) is a potent dissociative hallucinogen. Sought for recreational use as a novel psychoactive substance, it can also induce acute psychological agitation and pathophysiological cardiorespiratory effects. Due to the harms associated with its use, 3-MeO-PCP was added to the ‘Green List’ of materials covered by the 1971 Convention on Psychotropic Substances as a Schedule II substance by the United Nations Commission on Narcotic Drugs in April 2021. There have been 15 previous reports of fatal intoxications following 3-MeO-PCP use, but only one was attributable to 3-MeO-PCP intoxication alone. In this report we detail the first fatality due to 3-MeO-PCP intoxication to be reported in the UK, along with a review of the surrounding literature. Whilst the blood concentrations associated with 3-MeO-PCP toxicity and fatality remain unclear, by providing details of sample collection and storage conditions this case will aid in future interpretations. Furthermore, this case suggests that 3-MeO-PCP toxicity may be exacerbated by exercise. Users of 3-MeO-PCP should be cautioned against its use as a ‘club drug’ or in a similar setting where elevations in heart rate, body temperature and blood pressure may occur.</p

    The Story of the Meo People

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    Done by Thongsar, a Meo, it is an accurate interpretation of the Meo legend and histor

    Lao Project: The Meo of Xieng Khouang Province

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    Selection from a thesis describing the Meo, a cultural group living in Vietnam, Thailand, China and Laos.1. Chapters II and III of the author's Master's Thesis, Christianity: Innovation in Meo Culture. A Case Study in Missionization. University of Minnesota, 1957. 2. Laos Project; Paper #13; The Meo of Xieng Khouang Province; The period of field work was 1949-1953

    MEO SAR: System Concepts and Analysis

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    Existing microwave remote sensing instruments used for Earth observation face a clear tradeoff between spatial resolution and revisit times at global scales. The typical imaging capabilities of current systems range from daily observations at kilometer-scale resolutions provided by scatterometers to meter-scale resolutions at lower temporal rates (more than ten days) typical of synthetic aperture radars (SARs). A natural way to fill the gap between these two extremes is to use medium-Earth-orbit SAR (MEO-SAR) systems. MEO satellites are deployed at altitudes above the region of low Earth orbits (LEOs), ending at around 2000 km and below the geosynchronous orbits (GEOs) near 35 786 km. MEO SAR shows a clear potential to provide advantages in terms of spatial coverage, downlink visibility, and global temporal revisit times, e.g., providing moderate resolution images (some tens of meters) at daily rates. This article discusses the design tradeoffs of MEO SAR, including sensitivity and orbit selection. The use of these higher orbits opens the door to global coverage in one- to two-day revisit or continental/oceanic coverage with multidaily observations, making MEO SAR very attractive for future scientific missions with specific interferometric and polarimetric capabilities.Mathematical Geodesy and Positionin
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