17 research outputs found
Spirocyclic, macrocyclic and ladder complexes of coinage metals and mercury with dichalcogeno P2N2-supported anions
Financial support from the EPSRC and NSERC (Canada) is acknowledged.Metathetical reactions of alkali–metal derivatives of the dianion [tBuN(Se)P(μ-NtBu)2P(Se)NtBu]2− (2Se2−) with Ag(NHC)Cl, Ag[BF4], AuCl(THT) and HgCl2, as well as the reaction of 2S2− with AuCl(THT) were investigated. The observed products all incorporate the monoprotonated ligands 2SeH− or 2SH− in a variety of structural arrangements around the metal centres, including tetrameric and trimeric macrocycles [Ag and Au (E = Se)], a ladder (Au, E = S) and a spirocycle (Hg); the ladder contains both the dianion 2S2− and the monoanion 2SH− as ligands linking three Au2 units. All complexes have been characterised in the solid state by single crystal X-ray analyses and in solution by multinuclear (1H, 31P and 77Se) NMR spectra.PostprintPeer reviewe
5,5'-Azoxytetrazolates - a new nitrogen-rich dianion and its comparison to 5,5'-azotetrazolate
A modification of the synthesis of sodium 5,5'-azotetrazolate pentahydrate, described by Thiele in 1898, yields the unknown and unexpected corresponding 5N-oxido derivative sodium 5,5'-azoxybistetrazolate pentahydrate (Na(2)zTO center dot 5H(2)O, 1). Purification was achieved by recrystallization based on the better solubility of Na(2)zTO center dot 5H(2)O in water. Different nitrogen-rich salts, such as the diammonium (3), the dihydroxylammonium (4), the bis-diaminoguanidinium (5), the bis-triaminoguanidinium (6) and the diaminouronium salt (7), have been prepared using metathesis reactions starting from barium 5,5'azoxybistetrazolate pentahydrate (2) and ammonium, hydroxylammonium, diaminoguanidinium or diaminouronium sulfate and triaminoguanidinium chloride, respectively. The nitrogen rich azoxyderivatives 3-7 were characterized using NMR, IR and Raman spectroscopy, mass spectrometry and elemental analysis. Additionally the solid state structures of 3, 4, 5 and 7 were determined by single crystal X-ray diffraction. The heats of formation of 3 and 4 and their corresponding azo-tetrazolate derivatives were calculated by the atomization method based on CBS-4M enthalpies. With these values and the crystal densities, several detonation parameters such as the detonation velocity, detonation pressure and specific impulse were calculated (EXPLO5) and compared. The sensitivities towards shock (BAM drophammer), friction (BAM friction tester) and electrostatic discharge of the described compounds were determined
Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes
Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues
Longitudinal cerebral diffusion changes reflect progressive decline of language and cognition
Optical control of adenosine-mediated pain modulation
Adenosine receptors (ARs) play many important roles in physiology and have been recognized as potential targets for pain relief. Here, we introduce three photoswitchable adenosine derivatives that function as light-dependent agonists for ARs and confer optical control to these G protein-coupled receptors. One of our compounds, AzoAdenosine-3, was evaluated in the classical formalin model of pain. The molecule, active in the dark, was not metabolized by adenosine deaminase and effectively reduced pain perception in a light-dependent manner. These antinociceptive effects suggested a major role for A1R and A3R in peripheralmediated pain sensitization, whereas an average adenosine-mediated antinociceptive effect will be facilitated by A2AR and A2BR. Our results demonstrate that a photoswitchable adenosine derivative can be used to map the contribution of ARs mediating analgesia in vivo
За кадры. 1985. № 76 (2569)
22 декабря - День энергетикаМинистр - выпускник ТПИПредлагают геологи / Г. БровченкоТранспортникам нужна помощь / В. МакаренкоИстория партии и народа / Н. ШевченкоГоловоломка и другие задачи / Р. АкимоваНиже возможностей / Л. КалугинаОдин за всех / Н. Емельянович, Н. БогомоловаПервокурсники перед сессией / А. ГромаковКирпич будет прочнее / В. И. ВерещагинК новым рубежам / В. ЕреминСвет и тепло города / Н. Попов, Г. БекманНаступление на болезни / [беседа с] Т. И. ТеркинаВсегда в поиске / М. АркадьевОмскому литобъединению / Г. БородянскийВстреча с классикой / И. МороцкаяГости из Томск