Construction of Helical Structures with Multiple Fused Anthracenes: Structures and Properties of Long Expanded Helicenes

Author(s):  
Kei Fujise ◽  
Eiji Tsurumaki ◽  
Kan Wakamatsu ◽  
Shinji Toyota
2015 ◽  
Vol 231 ◽  
pp. 70-79 ◽  
Author(s):  
Lin Li ◽  
Chong-Bo Liu ◽  
Gao-Shan Yang ◽  
Zhi-Qiang Xiong ◽  
Hong Liu ◽  
...  

Author(s):  
R. M. McCombs ◽  
M. Benyesh-Melnick ◽  
J. P. Brunschwig

Measles virus is an agent that is capable of replicating in a number of different culture cells and generally causes the formation of multinucleated giant cells. As a result of infection, virus is released from the cells into the culture fluids and reinfection can be initiated by this cell-free virus. The extracellular virus has been examined by negative staining with phosphotungstic acid and has been shown to be a rather pleomorphic particle with a diameter of about 140 mμ. However, no such virus particles have been detected in thin sections of the infected cells. Rather, the only virus-induced structures present in the giant cells are eosinophilic inclusions (intracytoplasmic or intranuclear). These inclusion bodies have been shown to contain helical structures, resembling the nucleocapsid observed in negatively stained preparations.


2015 ◽  
Vol 53 (3) ◽  
pp. 198-205
Author(s):  
Bong-Ki Ryu ◽  
Su-Yeon Choi ◽  
Young-Seok Kim ◽  
Jong-Hwan Kim ◽  
Jae-Yeop Jung ◽  
...  

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.


Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>


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