On periodic homeomorphisms of spheres

The purpose of this paper is to study how small orbits of periodic homemorphisms of spheres can be.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol1/agt-1-22.abs.htm

Delivering strong 1H nuclear hyperpolarization levels and long magnetic lifetimes through signal amplification by reversible exchange

Hyperpolarization turns typically weak NMR and MRI responses into strong signals so that ordinarily impractical measurements become possible. The potential to revolutionize analytical NMR and clinical diagnosis through this approach reflect this area's most compelling outcomes. Methods to optimize the low cost parahydrogen based approach signal amplification by reversible exchange (SABRE) with studies on a series of biologically relevant nicotinamides and methyl nicotinates are detailed. These procedures involve specific 2H-labelling in both the agent and catalyst and achieve polarization lifetimes of ca. 2 minutes with 50% polarization in the case of 4,6-d2-methylnicotinate. As a 1.5 T hospital scanner has an effective 1H polarization level of just 0.0005% this strategy should result in compressed detection times for chemically discerning measurements that probe disease. To demonstrate this techniques generality, we exemplify further studies on a range of pyridazine, pyrimidine, pyrazine and isonicotinamide analogues that feature as building blocks in biochemistry and many disease treating drugs

Continuous selections of multivalued mappings

This survey covers in our opinion the most important results in the theory of continuous selections of multivalued mappings (approximately) from 2002 through 2012. It extends and continues our previous such survey which appeared in Recent Progress in General Topology, II, which was published in 2002. In comparison, our present survey considers more restricted and specific areas of mathematics. Note that we do not consider the theory of selectors (i.e. continuous choices of elements from subsets of topological spaces) since this topics is covered by another survey in this volume

Outline of fungi and fungus-like taxa

This article provides an outline of the classification of the kingdom Fungi (including fossil fungi. i.e. dispersed spores, mycelia, sporophores, mycorrhizas). We treat 19 phyla of fungi. These are Aphelidiomycota, Ascomycota, Basidiobolomycota, Basidiomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Entorrhizomycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. The placement of all fungal genera is provided at the class-, order- and family-level. The described number of species per genus is also given. Notes are provided of taxa for which recent changes or disagreements have been presented. Fungus-like taxa that were traditionally treated as fungi are also incorporated in this outline (i.e. Eumycetozoa, Dictyosteliomycetes, Ceratiomyxomycetes and Myxomycetes). Four new taxa are introduced: Amblyosporida ord. nov. Neopereziida ord. nov. and Ovavesiculida ord. nov. in Rozellomycota, and Protosporangiaceae fam. nov. in Dictyosteliomycetes. Two different classifications (in outline section and in discussion) are provided for Glomeromycota and Leotiomycetes based on recent studies. The phylogenetic reconstruction of a four-gene dataset (18S and 28S rRNA, RPB1, RPB2) of 433 taxa is presented, including all currently described orders of fungi.Fil: Wijayawardene, N. N.. Qujing Normal University; ChinaFil: Hyde, K. D.. Mae Fah Luang University; TailandiaFil: Al-Ani, L. K. T.. University of Baghdad; IraqFil: Tedersoo, L.. University of Tartu; EstoniaFil: Haelewaters, D.. University of South Bohemia; República Checa. Purdue University; Estados Unidos. Universidad Autónoma de Chiriquí; PanamáFil: Becerra, Alejandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Schnittler, M.. Ernst Moritz Arndt University Greifswald; AlemaniaFil: Shchepin, O. N.. The Komarov Botanical Institute of the Russian Academy of Sciences; RusiaFil: Novozhilov, Y. K.. The Komarov Botanical Institute of the Russian Academy of Sciences; RusiaFil: Silva-Filho, A.G. S.. Universidade Federal do Rio Grande do Norte; BrasilFil: Gentekaki, E.. Mae Fah Luang University; TailandiaFil: Liu, P.. Jilin Agricultural University; ChinaFil: Cavender, J. C.. Ohio University; Estados UnidosFil: Kang, Y.. Guizhou Medical University; ChinaFil: Mohammad, S.. Iranian Research Organization for Science and Technology; IránFil: Zhang, L. F.. Qujing Normal University; ChinaFil: Xu, R. F.. Qujing Normal University; ChinaFil: Li, Y. M.. Qujing Normal University; ChinaFil: Dayarathne, M. C.. Guizhou University; ChinaFil: Ekanayaka, A. H.. Mae Fah Luang University; TailandiaFil: Wen, T. C.. Guizhou University; ChinaFil: Deng, C. Y.. Guizhou Academy of Science; ChinaFil: Pereira, O. L.. Universidade Federal de Viçosa; BrasilFil: Navathe, S.. Agharkar Research Institute; IndiaFil: Hawksworth, D. L.. The Natural History Museum; Reino UnidoFil: Fan, X. L.. Beijing Forestry University; ChinaFil: Dissanayake, L. S.. Guizhou University; ChinaFil: Kuhnert, E.. Leibniz University Hannover; AlemaniaFil: Grossart, H. P.. Leibnitz Institute of Freshwater Ecology and Inland Fisheries; AlemaniaFil: Thines, M.. Senckenberg Biodiversity and Climate Research Centre; Alemani

Synthesis and hyperpolarisation of eNOS substrates for quantification of NO production by 1H NMR spectroscopy

Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of l-arginine into l-citrulline. NO is a free radical gas with a short half-life in vivo (≈5s), therefore direct NO quantification is challenging. An indirect method - based on quantifying conversion of an l-Arg- to l-Cit-derivative by 1H NMR spectroscopy - is herein proposed. A small library of pyridyl containing l-Arg derivatives was designed and synthesised. In vitro tests showed that compounds 4a-j and 11a-c were better or equivalent substrates for the eNOS enzyme (NO2 - production=19-46μM) than native l-Arg (NO2 - production=25μM). Enzymatic conversion of l-Arg to l-Cit derivatives could be monitored by 1H NMR. The maximum hyperpolarization achieved by SABRE reached 870-fold NMR signal enhancement, which opens up exciting future perspectives of using these molecules as hyperpolarized MRI tracers in vivo