Distribution of lignin and cellulose in compression wood tracheids of Pinus yunnanensis determined by fluorescence microscopy and confocal Raman microscopy

2013 ◽  
Vol 47 ◽  
pp. 212-217 ◽  
Author(s):  
Zhe Ji ◽  
Jian-Feng Ma ◽  
Zhi-Heng Zhang ◽  
Feng Xu ◽  
Run-Cang Sun
2012 ◽  
Vol 18 (6) ◽  
pp. 1459-1466 ◽  
Author(s):  
Zhiheng Zhang ◽  
Jianfeng Ma ◽  
Zhe Ji ◽  
Feng Xu

AbstractThe anatomy and topochemistry in normal and compression wood tracheid cell wall of Pinus bungeana Zucc. were investigated by fluorescence microscopy and confocal Raman microscopy. Using fluorescence microscopy, the severity of compression wood was classed as a mild type for the reason that it did not contain all compression wood features. Chemical imaging by confocal Raman microscopy was used for analyzing the distribution of lignin and cellulose, as well as the functional groups of lignin in tracheid cell walls. By comparison with normal wood, highly lignified outer S2 layer [S2(L)], thicker S1 layer, and obviously reduced lignification in the middle lamella were characteristic of compression wood. In addition, smaller microfibril angle was observed in the S2(L) region. The distribution of coniferyl alcohol and coniferyl aldehyde in normal and compression wood was enriched in S1 and S2 layers but lack in cell corner and/or S2L regions, which showed an opposite pattern to lignin distribution. Confocal Raman microscopy with high spatial resolution contributes to a further understanding of the differences between normal and compression wood in polymers distribution and molecules orientation in situ.


2018 ◽  
Vol 91 (1) ◽  
pp. 1049-1055 ◽  
Author(s):  
Carol Korzeniewski ◽  
Jay P. Kitt ◽  
Saheed Bukola ◽  
Stephen E. Creager ◽  
Shelley D. Minteer ◽  
...  

2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Jinping Dong ◽  
Greg Haugstad ◽  
Chris Frethem ◽  
John Foley ◽  
Bob Hoerr ◽  
...  

The ElectroNanospray process (Nanocopoeia, Inc) transforms drugs and polymers into many nanoscale material states including powders, liquids, encapsulated particles, and coatings. This allows application of polymers and drugs to the surface of medical devices such as coronary stents in a single-stage process. A model drug delivery system consisting of a polymer matrix (arborescent polyisobutylene-polystyrene, or arbIBS) and either dexamethasone or sirolimus was studied by various characterization techniques. Modification of ElectroNanospray process parameters resulted in surface coatings with rich morphologies that are revealed by SEM, Atomic Force Microscopy (AFM) and Confocal Raman Microscopy were employed to monitor the drug release process in situ, through which the mechanism of the drug-eluting process may be proposed. A Confocal Raman microscope fitted with underwater objective was used to image arbIBS∕drug films incubated in phosphate-buffered saline over 12h and at various film depths. Drug migrated from more concentrated areas into the surrounding polymer and toward the surface, beginning as early as 5min after placing the sample in buffer and continuing throughout the 12h period. High drug levels remained in the more concentrated areas at the end of incubation, suggesting the potential for prolonged release. SEM and AFM images taken from samples post incubation showed the appearance of nanoscale pores ∼100nm in diameter in areas corresponding in size and distribution to the Confocal Raman planar image areas of increased drug concentration. Confocal Raman microscopy offers a powerful new technique for demonstrating real-time drug release from therapeutic medical device coatings.


2012 ◽  
Vol 102 (2) ◽  
pp. 360-368 ◽  
Author(s):  
Katharina Klein ◽  
Alexander M. Gigler ◽  
Thomas Aschenbrenner ◽  
Roberto Monetti ◽  
Wolfram Bunk ◽  
...  

Author(s):  
M. Gomez-Lazaro ◽  
A. Freitas ◽  
C.C. Ribeiro

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