Evidence of accessory compounds in vessel walls of Sapelli heartwood (Entandrophragma cylindricum) obtained by transmission electron microscopy

Kleist, G.; Schmitt, Uwe

doi:10.1007/pl00002633

Cited by 40 publications

(19 citation statements)

References 4 publications

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“…From both, the impregnated and the control samples with sizes of 10 9 10 9 180 mm 3 , small blocks of 1 9 1 9 5 mm 3 were separated and directly embedded in Spurr's epoxy resin (Spurr 1969) under mild vacuum with several cycles of evacuation and ventilation as described by Kleist and Schmitt (1999). From these embedded blocks, transverse thin sections of 1 lm in thickness were prepared with a diamond knife and transferred onto a non-reflective quartz slide; a drop of non-UV-absorbing glycerine was added, and the sample was covered again with a non-reflective quartz slide.…”

Section: Detection Of Nmm With Subcellular Uv Microspectrophotometrymentioning

confidence: 99%

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

et al. 2012

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Methylated N-methylol melamine (NMM) is known for its ability to enhance physico-mechanical properties, anti-fungal ability, and hydrophobicity and was therefore used to impregnate two less used and non-durable wood species from Myanmar, Bombax ceiba and Bombax insigne. Solution uptake, weight percent gain and nitrogen content were increased by increasing melamine concentrations with B. ceiba always achieving higher values compared with B. insigne. According to the leaching results, a higher degree of condensation after curing as well as a better crosslinking of NMM could be obtained at higher temperatures. However, both curing temperatures used (90 and 120°C) resulted in almost the same amount of nitrogen fixed in the cell wall. UV microspectrophotometry confirmed the penetration of the NMM into different morphological regions of wood tissues, which was again supported by the analysis of point measurement spectra of treated and untreated specimens.

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Section: Detection Of Nmm With Subcellular Uv Microspectrophotometrymentioning

confidence: 99%

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

et al. 2012

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“…For each incubation time and the control samples, two replicates were made. The specimens were prepared with epoxy resin as embedding medium (Spurr 1969) as described by Kleist and Schmitt (1999).…”

Section: Cellular Uv-microspectrophotometry (Umsp)mentioning

confidence: 99%

Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 1: Aspects of delignification and surface hardness

et al. 2011

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The white rot fungus Physisporinus vitreus is currently tested for several biotechnological applications such as permeability improvement of refractory wood species or the optimization of the acoustic properties of wood for violins. The enzymatic activity of P. vitreus results in the degradation of pit membranes and simultaneous alterations of the tracheid cell wall structure in wood of Norway spruce wPicea abies (L.) Karstx. By this means, selective delignification and simultaneous degradation occur in the latewood tracheids at short incubation times. To study the delignification of individual cell wall layers in latewood tracheids, cellular UVmicrospectrophotometry was applied to wood of Norway spruce that had been incubated for between 3 and 9 weeks. By means of this technique, the progressing delignification was demonstrated in the latewood tracheid secondary walls. Moreover, local delignification in close proximity to hyphal tunneling, cavities, and notches was evident. Additionally, the mechanical changes were measured (a) at the macroscopic level by Brinell hardness test and (b) at the cellular level by nanoindentation. Brinell hardness was significantly reduced with increasing incubation time which was attributed to the partial delignification. Unlike Brinell tests, results from nanoindentation tests did not show a clear effect of fungal activity because of the material heterogeneity and the high spatial resolution of this technique. The present study provides methodological approaches for the investigation of wood-fungus interactions and contributes to a better understanding of the characteristics of wood decay at the subcellular level caused by the white rot fungus P. vitreus. Moreover, it establishes the basis for a subsequent chemical analysis, for which the results will be the topic of a second paper in this series.

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“…Untreated veneers served as control. The specimens were embedded in epoxy resin (Spurr 1969) under mild vacuum and several cycles of evacuation and ventilation as described by Kleist and Schmitt (1999). Sections, 1 µm thick, were prepared with a diamond knife, transferred to quartz microscope slides and immersed in glycerine.…”

Section: Uv Microspectrophotometry (Umsp)mentioning

confidence: 99%

Investigation on bonding quality of beech wood (Fagus orientalis L.) veneer during high temperature drying and aging

et al. 2011

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In the present study, the effects of high drying temperature and UV light induced aging on bonding quality of plywood manufactured from untreated and treated veneer layers were investigated. Rotary cut veneers with dimensions of 500 mm × 500 mm × 2 mm produced from beech (Fagus orientalis Lipsky) log were selected for topochemical, chemical and mechanical analyses. The veneer sheets were oven-dried at 100°C and 180°C after the peeling process. Afterwards, the surfaces were exposed to artificial UV irradiation in an UV chamber for 24 h, 48 h and 72 h representing natural sun irradiation of 2, 4 and 6 months, respectively. Topochemical distribution of lignin and phenolic extractives of the treated and untreated veneers was investigated on a cellular level using UV microspectrophotometry (UMSP). For the chemical characterization of accessory compounds high performance liquid chromatography (HPLC) was used. Furthermore, the shear and bending strengths of plywood manufactured from the treated samples are determined in order to study the bonding quality. The UV microscopic detection shows that after high drying temperature and aging treatment, lignin condensation occurs. With increasing drying temperature and aging duration, more phenolic extractives are situated in parenchyma cells and vessel lumens which can be proved by increased absorbance at 278 nm. The HPLC analysis of the treated tissue showed distinct signals of polymerized compounds such as catechin and 2,6-dimethoxybenzoquinone which are chromophoric compounds in discolored beech wood. The mechanical properties of plywood showed that with increasing drying temperature up to 180°C does not negatively affect shear and bending strengths of samples. After exposure of the veneers to UV irradiation (especially 6 months), decreasing shear and bending strengths of plywood samples can be observed. Untersuchung des Einflusses von Hoch-Temperaturtrocknung und Alterung auf die Verklebungseigenschaften von Buchen-Furniersperrholz (Fagus orientalis)Zusammenfassung In der vorliegenden Arbeit wurden die Verklebungseigenschaften von Sperrhölzern untersucht, die aus thermisch behandelten und UV-belichteten Schälfur-nieren hergestellt wurden. Für die Untersuchungen wurden Schälfurniere der Holzart Buche (Fagus orientalis, Format 500 × 500 × 2 mm 3 ) mit Temperaturen von 100°C und 180°C thermisch behandelt und die Oberflächen anschließend 24, 48 bzw. 72 Stunden künstlich belichtet, was einer natürlichen Sonneneinstrahlung von 2, 4 bzw. 6 Monaten entspricht. Das Holzgewebe der thermisch behandelten und UV-belichteten Furniere wurde im Vergleich zu unbehandelten Schälfurnieren topochemisch mit Hilfe der zellulä-ren Universalmikrospektralphotometrie (UMSP) analysiert, um Reaktionen des Lignins und phenolischer Extraktstoffe zu detektieren. Für die chemischen Analysen der Extraktstoffe wurden zusätzlich chromatographische Untersuchungen (HPLC-Chromatographie) durchgeführt. Zur Charakterisierung der Verklebungseigenschaften wurden Sperrhölzer 498 Eur. J. Wood Prod. (2012) 70:497-506 ...

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Evidence of accessory compounds in vessel walls of Sapelli heartwood (Entandrophragma cylindricum) obtained by transmission electron microscopy

Cited by 40 publications

References 4 publications

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 1: Aspects of delignification and surface hardness

Investigation on bonding quality of beech wood (Fagus orientalis L.) veneer during high temperature drying and aging

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