The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Mitsuo Takai - One of the best experts on this subject based on the ideXlab platform.
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cp mas 13c nmr study of cellulose and cellulose derivatives 1 complete assignment of the cp mas 13c nmr spectrum of the native cellulose
Journal of the American Chemical Society, 2002Co-Authors: Hiroyuki Kono, Shunji Yunoki, Tamio Shikano, Masashi Fujiwara, Tomoki Erata, Mitsuo TakaiAbstract:The precise assignments of cross polarization/magic angle spinning (CP/MAS) 13C NMR spectra of cellulose Iα and Iβ were performed by using 13C labeled cellulose biosynthesized by Acetobacter xylinum (A. xylinum) ATCC10245 strain from culture medium containing d-[1,3-13C]glycerol or d-[2-13C]glucose as a carbon source. On the CP/MAS 13C NMR spectrum of cellulose from d-[1,3-13C]glycerol, the introduced 13C labeling were observed at C1, C3, C4, and C6 of the biosynthesized cellulose. In the case of cellulose biosynthesized from d-[2-13C]glucose, the transitions of 13C labeling to C1, C3, and C5 from C2 were observed. With the quantitative analysis of the 13C transition ratio and comparing the CP/MAS 13C NMR spectrum of the Cladophora cellulose with those of the 13C labeled celluloses, the assignments of the cluster of resonances which belong to C2, C3, and C5 of cellulose, which have not been assigned before, were performed. As a result, all carbons of cellulose Iα and Iβ except for C1 and C6 of cellulose I...
Willem Back - One of the best experts on this subject based on the ideXlab platform.
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the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine
Equine Veterinary Journal, 2010Co-Authors: J Sleutjens, Inge D. Wijnberg, Johannes H Van Der Kolk, George Voorhout, Willem BackAbstract:Summary Reasons for performing study: In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown. Objectives: To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine. Methods: Computed tomography was performed on 6 cadaver cervical spines from adult Warmblood horses subjected to euthanasia for reasons unrelated to cervical spine abnormalities, in a neutral position, in 20 and 40° extension, and in 20 and 40° flexion. Multiplanar reconstructions were made to obtain transverse images perpendicular to the long axis of each pair of intervertebral foramina from C2–T1. Intervertebral foramina dimensions were measured in the 5 positions. Results: Compared to the neutral position, 40° extension caused a decrease in foramina dimensions at segments C4–C5, C5–C6, C6–C7 (P<0.001) and C7–T1 (P<0.002); 20° extension caused a decrease in foramina dimensions at segments C5–C6 (P<0.02), C6–C7 (P<0.001) and C7–T1 (P<0.01); 20° flexion caused an increase in foramen length at segment C6–C7 (P<0.01). Conclusions:Ex vivo extension of the cervical spine causes a decrease in intervertebral foramina dimensions at segments C4–T1, similar to that found in man. Potential relevance:In vivo extension of the cervical spine could possibly interfere with peripheral nerve functioning at segments C4–T1. This effect may be even more profound in patients with a reduced intervertebral foramina space, for example in the presence of facet joint arthrosis.
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The effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine
Equine Veterinary Journal, 2010Co-Authors: J Sleutjens, Inge D. Wijnberg, Johannes H Van Der Kolk, George Voorhout, Willem BackAbstract:Summary Reasons for performing study: In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown. Objectives: To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine. Methods: Computed tomography was performed on 6 cadaver cervical spines from adult Warmblood horses subjected to euthanasia for reasons unrelated to cervical spine abnormalities, in a neutral position, in 20 and 40° extension, and in 20 and 40° flexion. Multiplanar reconstructions were made to obtain transverse images perpendicular to the long axis of each pair of intervertebral foramina from C2–T1. Intervertebral foramina dimensions were measured in the 5 positions. Results: Compared to the neutral position, 40° extension caused a decrease in foramina dimensions at segments C4–C5, C5–C6, C6–C7 (P
Hong Wei Hou - One of the best experts on this subject based on the ideXlab platform.
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Significant positional isomeric effect on structural assemblies of Zn(II) and Cd(II) coordination polymers based on bromoisophthalic acids and various dipyridyl-type coligands
Crystal Growth and Design, 2011Co-Authors: Lu Fang Ma, Xiu Qin Li, Qing-lei Meng, Miao Du, Ling Wang, Hong Wei HouAbstract:Seven Zn(II) and Cd(II) coordination polymers, formulated as {[Zn-2(5-Br-ip)(2)(bpy)(H2O)]center dot 2H(2)O}(n) (1), {[Zn(5-Br-ip)(bpa)(H2O)]}(n) (2), {[Cd(5-Br-ip)(bpp)(H2O)]}(n) (3), {[Zn(5-Br-ip)(bpe)]}(n) (4), {[Zn-2(4-Br-ip)(2)(bpy)]center dot H2O} (5), {[Zn(4-Br-ip)(bpa)(H2O)]}(n) (6), and {[Cd(4-Br-ip)(bpp)]} (7), were prepared by hydrothermal reactions based on 4-bromo- or 5-bromo-isophtlialic acid (4-Br-H(2)ip or 5-Br-H(2)ip) and different dipyridyl-type coligands 4,4'-bipyridyl (bpy), 1,2-bi(4-pyridyl)ethane (bpa), 1,3-di(4-pyridyl)propane (bpp), and 1,2-di(4-pyridyl)ethene (bpe). All complexes 1-7 were characterized by elemental analysis, IR spectra, and X-ray single-crystal diffraction. Complex 1 is a 2D (6,3) coordination network and further assembled into a 3D framework via pi-pi. stacking interactions. Complex 2 shows a 1D coordination array and further forms a 2D supra-molecular network via H-bonding interactions. Complex 3 has a 2-fold interpenetrating 3D diamond framework. Complex 4 is a 3-fold interpenetrating 3D network with CdSO4 topology, constructed from alternately left- and right-handed helical arrays. Complex 5 has a 3D (3,4)-connected network with (4 82)(4.8(2).10(3)) topology. Complex 6 features a I D coordination chain and further forms a 2D helical supramolecular pattern by H-bonding. Complex 7 exhibits a (3,5)-connected 2D layer with the Schlafli symbol of (4(2).6) (4(2).6(7).8). The results reveal that the diverse coordination networks of 1-7 can be adjusted by the different dispositions of the -Br substituent of isophthalate building blocks, as well as the metal ions and the dipyridyl coligands. Moreover, the luminescent properties of the complexes have been investigated.
Fatih Semerci - One of the best experts on this subject based on the ideXlab platform.
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a two dimensional photoluminescent cadmium ii coordination polymer containing a new coordination mode of pyridine 2 3 dicarboxylate synthesis structure and molecular simulations for gas storage and separation applications
Polyhedron, 2013Co-Authors: Fatih Semerci, Okan Zafer Yesilel, Mustafa Serkan Soylu, Seda Keskin, Orhan BuyukgungorAbstract:Abstract A novel two-dimensional (2D) coordination polymer, [Cd(μ-pydc)(2-meim)]n (1) (pydc = pyridine-2,3-dicarboxylate, 2-meim = 2-methylimidazole) was synthesized and characterized by spectral methods (FT-IR and photoluminescence), elemental analysis, thermal analysis (TG, DTG and DTA) and single crystal X-ray diffraction techniques. Complex 1 displays a 2D layer structure through the linkage of bridging carboxyl oxygen and pyridine nitrogen atoms of the pydc ligand. Each Cd(II) center exhibits a distorted octahedral coordination environment with four carboxylate oxygen atoms and two nitrogen atoms from the pydc and 2-meim ligands. In 1, the pydc ligand exhibits a new coordination mode. The distances of adjacent Cd(II) atoms are 3.679 and 7.742 A. The 2D layers are further linked by C–H⋯π and π⋯π stacking to construct a 3D supramolecular structure. In order to assess the potential of 1 in gas storage and gas separation applications, molecular simulations were performed. Furthermore, 1 exhibits blue photoluminescence in the solid state at room temperature.
Hiroyuki Kono - One of the best experts on this subject based on the ideXlab platform.
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cp mas 13c nmr study of cellulose and cellulose derivatives 1 complete assignment of the cp mas 13c nmr spectrum of the native cellulose
Journal of the American Chemical Society, 2002Co-Authors: Hiroyuki Kono, Shunji Yunoki, Tamio Shikano, Masashi Fujiwara, Tomoki Erata, Mitsuo TakaiAbstract:The precise assignments of cross polarization/magic angle spinning (CP/MAS) 13C NMR spectra of cellulose Iα and Iβ were performed by using 13C labeled cellulose biosynthesized by Acetobacter xylinum (A. xylinum) ATCC10245 strain from culture medium containing d-[1,3-13C]glycerol or d-[2-13C]glucose as a carbon source. On the CP/MAS 13C NMR spectrum of cellulose from d-[1,3-13C]glycerol, the introduced 13C labeling were observed at C1, C3, C4, and C6 of the biosynthesized cellulose. In the case of cellulose biosynthesized from d-[2-13C]glucose, the transitions of 13C labeling to C1, C3, and C5 from C2 were observed. With the quantitative analysis of the 13C transition ratio and comparing the CP/MAS 13C NMR spectrum of the Cladophora cellulose with those of the 13C labeled celluloses, the assignments of the cluster of resonances which belong to C2, C3, and C5 of cellulose, which have not been assigned before, were performed. As a result, all carbons of cellulose Iα and Iβ except for C1 and C6 of cellulose I...
