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https://www.readbyqxmd.com/read/27774727/simultaneous-chain-growth-and-step-growth-polymerization-of-methoxystyrenes-by-rare-earth-catalysts
#1
Xiaochao Shi, Masayoshi Nishiura, Zhaomin Hou
The simultaneous chain-growth and step-growth polymerization of a monomer is of great interest and importance because it can produce unique macromolecules which are difficult to prepare by other means. However, such a transformation is usually difficult to achieve in one polymerization system because chain-growth polymerization and step-growth polymerization proceed by different reaction mechanisms. Reported here is the simultaneous chain-growth and step-growth polymerization of para- and meta-methoxystyrenes catalyzed by half-sandwich rare-earth alkyl complexes, and the step-growth polymerization proceeds by the C-H polyaddition of anisyl units to vinyl groups...
November 14, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27442536/development-and-validation-of-high-resolution-melting-markers-derived-from-rysto-sts-markers-for-high-throughput-marker-assisted-selection-of-potato-carrying-rysto
#2
Xianzhou Nie, Darcy Sutherland, Virginia Dickison, Mathuresh Singh, Agnes M Murphy, David De Koeyer
Sequence analysis of the chromosome region harboring the sequence-tagged site (STS) markers YES3-3A and YES3-3B for Rysto, a gene responsible for extreme resistance to Potato virus Y (PVY) in potato, was performed in tetraploid potato 'Barbara' (Rrrr) and 'AC Chaleur' (rrrr) as well as their progeny selections. Three and two sequence variants were identified in Barbara resistant (R) selections and AC Chaleur susceptible (S) selections, respectively. Further analysis indicates that the variant with a 21-nucleotide (nt) deletion is likely the chromosome copy harboring the STS markers...
November 2016: Phytopathology
https://www.readbyqxmd.com/read/27181650/sensing-lymphoma-cells-based-on-a-cell-penetrating-apoptosis-inducing-electron-transfer-peptide-probe
#3
Kazuharu Sugawara, Hiroki Shinohara, Toshihiko Kadoya, Hideki Kuramitz
To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y4). A peptide whereby Y4C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH2) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells...
June 14, 2016: Analytica Chimica Acta
https://www.readbyqxmd.com/read/27150577/regio-and-stereochemical-control-in-ocimene-polymerization-by-half-sandwich-rare-earth-metal-dialkyl-complexes
#4
Deqian Peng, Gaixia Du, Pengfei Zhang, Bo Yao, Xiaofang Li, Shaowen Zhang
The polymerization of ocimene has been first achieved by half-sandwich rare-earth metal dialkyl complexes in combination with activator and Al(i) Bu3 . The regio- and stereoselectivity in the ocimene polymerization can be controlled by tuning the cyclopentadienyl ligand and the central metal of the complex. The chiral cyclopentadienyl-ligated Sc complex 1 prepares syndiotactic cis-1,4-polyocimene (cis-1,4-selectivity up to 100%, rrrr = 100%), while the corresponding Lu, Y, and Dy complexes 2-4 and the achiral pentamethylcyclopentadienyl Sc, Lu, and Y complexes 5-7 afford isotactic trans-1,2-polyocimenes (trans-1,2-selectivity up to 100%, mm = 100%)...
June 2016: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/26135988/synthesis-and-unique-reversible-splitting-of-14-membered-cyclic-aminomethylphosphines-on-to-7-membered-heterocycles
#5
Elvira I Musina, Tatiana I Fesenko, Igor D Strelnik, Fedor M Polyancev, Shamil K Latypov, Peter Lönnecke, Evamarie Hey-Hawkins, Andrey A Karasik, Oleg G Sinyashin
A novel type of 14-membered cyclic polyphosphine, namely 1,8-diaza-3,6,10,13-tetraphosphacyclotetradecanes 2a–4ahas been synthesized by the condensation of 1,2-bis(phenylphosphino)ethane, formaldehyde and alkylamines (isopropylamine, ethylamine and cyclohexylamine) as a RRRR/SSSS-stereoisomer. The structure of macrocycle 2a was investigated by NMR-spectroscopy and X-ray crystal structure analysis. The unique reversible processes of macrocycles 2a–4a splitting onto the corresponding rac- (2b–4b) and meso- (2c–4c) stereoisomers of 1-aza-3,6-diphosphacycloheptanes were discovered...
August 14, 2015: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/25165120/the-autotetraploid-fish-derived-from-hybridization-of-carassius-auratus-red-var-female-%C3%A3-megalobrama-amblycephala-male
#6
Qinbo Qin, Yude Wang, Juan Wang, Jing Dai, Jun Xiao, Fangzhou Hu, Kaikun Luo, Min Tao, Chun Zhang, Yun Liu, Shaojun Liu
The establishment of the tetraploid organism is difficult but useful in genetics and breeding. In the present study, we have artificially established an autotetraploid fish line (F2-F8) derived from the distant hybridization of Carassius auratus red var. (RR, 2n = 100) (female) × Megalobrama amblycephala (BB, 2n = 48) (male). The autotetraploid line (F2-F8) possess four sets of chromosomes from red crucian carp (RRRR, 4n = 200) and produce diploid ova and diploid sperm, which maintains the formation of the autotetraploid line...
October 2014: Biology of Reproduction
https://www.readbyqxmd.com/read/25017488/alternating-stereoselective-self-assembly-of-ssss-rrrr-or-rssr-isomers-of-tetrakisphosphines-in-the-row-of-14-16-18-and-20-membered-macrocycles
#7
Roman N Naumov, Elvira I Musina, Kirill B Kanunnikov, Tatiana I Fesenko, Dmitry B Krivolapov, Igor A Litvinov, Peter Lönnecke, Evamarie Hey-Hawkins, Andrey A Karasik, Oleg G Sinyashin
Novel 18- and 20-membered P,N-macrocycles have been obtained stereoselectively by covalent self-assembly of α,ω-bisphosphines, formaldehyde and benzylamine. Alternating SSSS/RRRR or RSSR diastereomers were formed in the row of the 14-, 16-, 18- and 20-membered macrocyclic aminomethylphosphines. For the first time it was demonstrated that the stereochemical result of the reaction depends on the even or odd number of the methylene groups between the two chiral phosphorus atoms in the initial α,ω-bisphosphines...
September 7, 2014: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/24193483/stabilization-of-tetraploid-triticale-with-chromosomes-from-triticum-aestivum-abd-abd-rr-2n-28
#8
U Hohmann
F1 hybrids with the genome constitution ABDERR (2n = 6x = 42) or ABDE(AB)RR (2n = 7x = 49), selected from crosses between either an octoploid Triticum aestivum/Thinopyrum elongatun amphiploid and tetraploid Secale cereale (AABBDDEE x RRRR) or autoallohexaploid triticale [AABBDDEE x (AB)(AB)RRRR], were backcrossed to tetraploid triticale (AB)(AB)RR and selfed for six generations. Thirty-three different tetraploid F6 progenies were karyotyped using C-banding. The aneuploidy frequency was 6.6% with 4.0% hypoploids and 2...
April 1993: TAG. Theoretical and Applied Genetics. Theoretische und Angewandte Genetik
https://www.readbyqxmd.com/read/24186020/spontaneous-hybridization-between-a-male-sterile-oilseed-rape-and-two-weeds
#9
F Eber, A M Chèvre, A Baranger, P Vallée, X Tanguy, M Renard
Spontaneous interspecific hybrids were produced under natural conditions (pollination by wind and bees) between a male-sterile cybrid Brassica napus (AACC, 2n = 38) and two weeds Brassica adpressa (AdAd, 2n = 14) and Raphanus raphanistrum (RrRr, 2n = 18). After characterization by chromosome counts and isozyme analyses, we observed 512 and 3 734 inter-specific seeds per m(2) for the B. napus-B. adpressa and B. napus-R. raphanistrum trials respectively. Most of the hybrids studied had the expected triploid structure (ACX)...
June 1994: TAG. Theoretical and Applied Genetics. Theoretische und Angewandte Genetik
https://www.readbyqxmd.com/read/24147755/anion-and-solvent-induced-chirality-inversion-in-macrocyclic-lanthanide-complexes
#10
Aleksandra Gerus, Katarzyna Slepokura, Jerzy Lisowski
A series of the lanthanide(III) or yttrium(III) complexes of the type [LnL(NO3)(H2O)2](NO3)2, [LnL(NO3)(H2O)](NO3)2, [LnL(H2O)2](NO3)3, and [LnLCl(H2O)2]Cl2 where L is an all-R or all-S enantiomer (L(R) or L(S)) of the chiral hexaaza macrocycle, 2(R),7(R),18(R),23(R)- or 2(S),7(S),18(S),23(S)-1,8,15,17,24,31-hexaazatricyclo[25.3.1.1.0.0]-dotriaconta-10,12,14,26,28,30-hexaene, and Ln(III) = Sm(III), Tb(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III), or Y(III), have been synthesized and structurally characterized...
November 4, 2013: Inorganic Chemistry
https://www.readbyqxmd.com/read/24116060/multiple-protein-domains-contribute-to-nuclear-import-and-cell-toxicity-of-dux4-a-candidate-pathogenic-protein-for-facioscapulohumeral-muscular-dystrophy
#11
Edgardo Daniel Corona, Daniela Jacquelin, Laura Gatica, Alberto Luis Rosa
DUX4 (Double Homeobox Protein 4) is a nuclear transcription factor encoded at each D4Z4 unit of a tandem-repeat array at human chromosome 4q35. DUX4 constitutes a major candidate pathogenic protein for facioscapulohumeral muscular dystrophy (FSHD), the third most common form of inherited myopathy. A low-level expression of DUX4 compromises cell differentiation in myoblasts and its overexpression induces apoptosis in cultured cells and living organisms. In this work we explore potential molecular determinants of DUX4 mediating nuclear import and cell toxicity...
2013: PloS One
https://www.readbyqxmd.com/read/24061771/introgression-of-a-and-b-genome-of-tetraploid-triticale-chromatin-into-tetraploid-rye
#12
H Wiśniewska, M Kwiatek, S Kulak-Książczyk, B Apolinarska
An improvement of rye is one of the mainstream goals of current breeding. Our study is concerned with the introduction of the tetraploid triticale (ABRR) into the 4x rye (RRRR) using classical methods of distant crossing. One hundred fifty BC1F9 hybrid plants [(4x rye × 4x triticales) × 4x rye] obtained from a backcrossing program were studied. The major aim of this work was to verify the presence of an introgressed A- and B- genome chromatin of triticale in a collection of the 4x rye-tiritcale hybrids and to determine their chromosome compositions...
November 2013: Journal of Applied Genetics
https://www.readbyqxmd.com/read/23902370/small-angle-x-ray-scattering-investigation-of-norbornene-terminated-syndiotactic-polypropylene-and-corresponding-comb-like-poly-macromonomer
#13
Finizia Auriemma, Claudio De Rosa, Rocco Di Girolamo, Amelia Silvestre, Amelia M Anderson-Wile, Geoffrey W Coates
The structure and crystallization properties of a norbornene end-functionalized syndiotactic polypropylene (sPP) macromonomer (MMsPP) with [rrrr] = 80 mol % and molecular mass Mn = 3600 g/mol and corresponding comb-like poly(macromonomer) (pMMsPP) with Mn = 100000 g/mol have been investigated using wide angle (WAXS) and small angle (SAXS) X-ray scattering, atomic force (AFM), transmission electron (TEM), and optical (OM) microscopy. The analysis reveals the tendency of the macromonomer and poly(macromonomer) to form structures characterized by layers of sPP chains alternated to layers occupied by the cyclic groups (norbornene or polynorbornene), and a small degree of interdigitation of sPP chains belonging to adjacent layers facing each other in an end-to-end arrangement...
September 5, 2013: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/23737500/trafficking-of-plant-vacuolar-invertases-from-a-membrane-anchored-to-a-soluble-status-understanding-sorting-information-in-their-complex-n-terminal-motifs
#14
Li Xiang, Wim Van den Ende
Vacuolar invertases (VIs) are highly expressed in young tissues and organs. They may have a substantial regulatory influence on whole-plant metabolism as well as on photosynthetic efficiency. Therefore, they are emerging as potentially interesting biotechnological targets to increase plant biomass production, especially under stress. On the one hand, VIs are well known as soluble and extractable proteins. On the other hand, they contain complex N-terminal propeptide (NTPP) regions with a basic region (BR) and a transmembrane domain (TMD)...
August 2013: Plant & Cell Physiology
https://www.readbyqxmd.com/read/22978886/onset-and-offset-specific-effects-in-interaural-level-difference-discrimination
#15
G Christopher Stecker, Andrew D Brown
The relative sensitivity of human listeners to interaural level differences (ILDs) carried by the onsets, offsets, and interior portions of brief sounds was examined. Stimuli consisted of single 4000-Hz Gabor clicks (Gaussian-windowed tone bursts) or trains of 16 such clicks repeating at an interclick interval (ICI) of 2 or 5 ms. In separate conditions, ILDs favored the right ear by a constant amount for all clicks (condition RRRR) or a changing amount that was maximal at sound onset (condition R000), offset (condition 000R), both onset and offset (condition R00R), or at the temporal midpoint of the stimulus (condition 0RR0)...
September 2012: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/22282393/rare-earth-metal-hydrocarbyl-complexes-bearing-linked-cyclopentadienyl-or-fluorenyl-ligands-synthesis-catalyzed-styrene-polymerization-and-structure-reactivity-relationship
#16
Zhongbao Jian, Dongmei Cui, Zhaomin Hou
A series of rare-earth-metal-hydrocarbyl complexes bearing N-type functionalized cyclopentadienyl (Cp) and fluorenyl (Flu) ligands were facilely synthesized. Treatment of [Y(CH(2)SiMe(3))(3)(thf)(2)] with equimolar amount of the electron-donating aminophenyl-Cp ligand C(5)Me(4)H-C(6)H(4)-o-NMe(2) afforded the corresponding binuclear monoalkyl complex [({C(5)Me(4)-C(6)H(4)-o-NMe(μ-CH(2))}Y{CH(2)SiMe(3)})(2)] (1a) via alkyl abstraction and C-H activation of the NMe(2) group. The lutetium bis(allyl) complex [(C(5)Me(4)-C(6)H(4)-o-NMe(2))Lu(η(3)-C(3)H(5))(2)] (2b), which contained an electron-donating aminophenyl-Cp ligand, was isolated from the sequential metathesis reactions of LuCl(3) with (C(5)Me(4)-C(6)H(4)-o-NMe(2))Li (1 equiv) and C(3)H(5)MgCl (2 equiv)...
February 27, 2012: Chemistry: a European Journal
https://www.readbyqxmd.com/read/22169034/enantioselective-cleavage-of-supercoiled-plasmid-dna-catalyzed-by-chiral-macrocyclic-lanthanide-iii-complexes
#17
Artur Krężel, Jerzy Lisowski
The enantiomers of the Sm (III), Eu (III) and Yb (III) complexes [LnL(NO(3))(2)](NO(3)) of a chiral hexaazamacrocycle were tested as catalysts for the hydrolytic cleavage of supercoiled plasmid DNA. The catalytic activity was remarkably enantioselective; while the [LnL(SSSS)(NO(3))(2)](NO(3)) enantiomers promoted the cleavage of plasmid pBR322 from the supercoiled form (SC) to the nicked form (NC), the [LnL(RRRR)(NO(3))(2)](NO(3)) enantiomers were inactive. Kinetics of plasmid DNA hydrolysis was also investigated by agarose electrophoresis and it indicated typical single-exponential cleavage reaction...
February 2012: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/22066998/localization-and-activity-of-the-calcineurin-catalytic-and-regulatory-subunit-complex-at-the-septum-is-essential-for-hyphal-elongation-and-proper-septation-in-aspergillus-fumigatus
#18
Praveen Rao Juvvadi, Jarrod R Fortwendel, Luise E Rogg, Kimberlie A Burns, Scott H Randell, William J Steinbach
Calcineurin, a heterodimer composed of the catalytic (CnaA) and regulatory (CnaB) subunits, plays key roles in growth, virulence and stress responses of fungi. To investigate the contribution of CnaA and CnaB to hyphal growth and septation, ΔcnaB and ΔcnaAΔcnaB strains of Aspergillus fumigatus were constructed. CnaA colocalizes to the contractile actin ring early during septation and remains at the centre of the mature septum. While CnaB's septal localization is CnaA-dependent, CnaA's septal localization is CnaB-independent, but CnaB is required for CnaA's function at the septum...
December 2011: Molecular Microbiology
https://www.readbyqxmd.com/read/21942299/cubane-type-fe4s4-clusters-with-chiral-thiolate-ligation-formation-by-ligand-substitution-detection-of-intermediates-by-1h-nmr-and-solid-state-structures-including-spontaneous-resolution-upon-crystallization
#19
Wayne Lo, Shaw Huang, Shao-Liang Zheng, R H Holm
Cubane-type clusters [Fe(4)S(4)(SR*)(4)](2-) containing chiral thiolate ligands with R* = CH(Me)Ph (1), CH(2)CH(Me)Et (2), and CH(2)CH(OH)CH(2)OH (3) have been prepared by ligand substitution in the reaction systems [Fe(4)S(4)(SEt)(4)]/R*SH (1-3, acetonitrile) and [Fe(4)S(4)Cl(4)](2-)/NaSR*(3, Me(2)SO). Reactions with successive equivalents of thiol or thiolate generate the species [Fe(4)S(4)L(4-n)(SR*)(n)](2-) (L = SEt, Cl) with n = 1-4. Clusters 1 and 2 were prepared with racemic thiols leading to the possible formation of one enantiomeric pair (n = 1) and seven diastereomers and their enantiomers (n = 2-4)...
November 7, 2011: Inorganic Chemistry
https://www.readbyqxmd.com/read/21591800/enantiomeric-self-recognition-in-homo-and-heterodinuclear-macrocyclic-lanthanide-iii-complexes
#20
Jerzy Lisowski
The controlled formation of lanthanide(III) dinuclear μ-hydroxo-bridged [Ln(2)L(2)(μ-OH)(2)X(2)](n+) complexes (where X = H(2)O, NO(3)(-), or Cl(-)) of the enantiopure chiral macrocycle L is reported. The (1)H and (13)C NMR resonances of these complexes have been assigned on the basis of COSY, NOESY, TOCSY, and HMQC spectra. The observed NOE connectivities confirm that the dimeric solid-state structure is retained in solution. The enantiomeric nature of the obtained chiral complexes and binding of hydroxide anions are reflected in their CD spectra...
June 20, 2011: Inorganic Chemistry
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