PHOTOCHEMICAL ISOMERIZATION OF CINNAMIC ACID IN AQUEOUS SOLUTIONS

1962 ◽  
Vol 66 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Bert H. Clampitt ◽  
James W. Callis
2015 ◽  
Vol 192 ◽  
pp. 271-278 ◽  
Author(s):  
Ana C. Silveira ◽  
Glaucia C. Moreira ◽  
Francisco Artés ◽  
Encarna Aguayo

2012 ◽  
Vol 184-185 ◽  
pp. 868-871
Author(s):  
Jing Liu

Series of the triazene-cinnamic acid polymeric fluorescent brighteners were synthesized through three-step condensation reactions and polymerization reaction with styrene under replacing one of amino compounds of traditional fluorescent brighteners by cinnamic acid. The optical properties in aqueous solutions and N,N’- dimethyl formamide as well as paper coating application test were evaluated. The results showed that the light stability and fluorescence quantum yield of polymeric fluorescent brighteners was improved obviously and photoinduced isomerization was lower. Meanwhile the optical properties of polymeric fluorescent brightener were affected by concentration and solvent polarity, fluorescence quantum yield increasing and hypochromatic shift of fluorescence emmission wavelength with the decrease of solvent polarity. When the concentration was over 1 10-4 g/mL, the fluorescence was quenched.


Author(s):  
K. J. Böhm ◽  
a. E. Unger

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:


Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.


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