bluuebunny/crossref_metadata_2025 huggingface dataset:
Kidney Retrieval Conditions Influence Damage to Renal Medulla:
Evaluation by Proton Nuclear Magnetic Resonance (NMR) Spectroscopy
Authors: Hauet Thierry , Gibelin Hélène , Godart Catherine , Eugene Michel , Carretier Michel
Published: October 2004

In the present investigation, the influence of retrieval
condition on medullary damage in kidneys was assessed.
The isolated perfused pig kidney was used to
assess initial renal function from multiorgan donors or
single organ donors after cold flush and 24 h cold storage
preservation with two preservation solutions:
Euro-Collins and University of Wisconsin solutions.
Kidneys flushed with cold heparinized saline and immediately
perfused were used as a control group. Kidneys
were perfused for 90 min at 37.5°C and renal perfusion
flow rate, glomerular filtration rate, tubular
reabsorption of Na+ and lactate dehydrogenase and N-acetyl-β-D-glucosaminidase excretion were determined.
Ischaemia reperfusion impairment was also
determined by 1H NMR (proton nuclear magnetic resonance)
spectroscopy. Renal function was significantly
decreased in experimental groups when compared to
the control group, but there was no significant difference
between experimental groups after 24 h cold
storage. The release of lactate dehydrogenase in the
effluent and the urinary excretion of N-acetyl-β-D-glucosaminidase
were not significantly different after 24
h cold storage. The most relevant resonances determined
by 1H NMR spectroscopy were citrate, trimethylamine-N-oxide, lactate, acetate and amino acids. Excretion
of these markers was significantly different
when compared to biochemical markers. A resonance
P (Peak) detected particularly in Euro-Collins solution
multiorgan donors after 24 h cold storage was identified
and well correlated to renal dysfunction. N-acetyl-β-D-glucosaminidase spectroscopy, which is a non-invasive
and non-destructive technique, is more efficient
to assess renal damage than conventional histology
and biochemical analysis.
Citrate, Acetate and Renal Medullary Osmolyte Excretion in Urine as
Predictor of Renal Changes after Cold Ischaemia and Transplantation
Authors: Hauet Thierry , Baumert Hervé , Gibelin Hélène , Godart Catherine , Carretier Michel , Eugene Michel
Published: October 2004

In organ transplantation, the determination of reliable
parameters to assess ischaemic damage is essential to
predict renal injury after preservation. The aim of this
study was to assess renal medullary injury by 1H NMR
(proton nuclear magnetic resonance) spectroscopy after
preservation and reperfusion. Three experimental
groups of pigs were examined during a 2-week period:
control group (n = 4), Euro-Collins group (EC) (cold
flushed and 48 h cold storage of kidney in EC and autotransplantation,
n = 7), and University of Wisconsin
(UW) group (cold flushed and 48 h cold storage of kidney
in UW and autotransplantation, n = 7). Creatinine
and urea were improved in the two cold stored groups.
The most relevant resonances determined by 1H NMR
spectroscopy after transplantation were those arising
from citrate and acetate in urine and trimethylamine-N-oxide (TMAO) in urine and plasma. We demonstrate
that graft dysfunction is associated with damage to the
renal medulla as determined by TMAO release in urine
and plasma. Conversely, citrate excretion can discriminate
kidneys with favourable outcome. This study outlines
the specific and beneficial impact of UW solution
on renal preservation and suggests that 1H NMR spectroscopy
is efficient both to detect ischaemic damage
of preserved kidneys and to discriminate the preservation
quality between different preservation solutions.
Assessment of Non-Heart-Beating Donor (NHBD) Kidneys for Viability on Machine Perfusion
Authors: Balupuri Shlokarth , Buckley Pamela , Mohamed Mostafa , Cornell Chris , Mantle David , Kirby John , Manas Derek M. , Talbot David
Published: October 2004

The shortage of organs has resulted in renewed interest in organs from non-heart-beating donors (NHBD). Viability assessment of such organs may reduce the incidence of delayed graft function and primary nonfunction. In Phase III of the NHBD programme, introduction of machine perfusion enabled the assessment of these marginal donors. Since then the graft survival has been 88.4% compared with the previous phase where machine perfusion or viability assessment was not done (45.5%). The parameters used were total glutathione S-transferase (GST) in the perfusate, the intrarenal vascular resistance (IRVR) and flow characteristics over time.

Methods: All NHBD kidneys were machine perfused through a locally developed perfusion system. The viability was assessed by serial measurements of the above-mentioned parameters.

Results: Forty-two local NHBD kidneys were retrieved and one kidney was imported, of which 19 donors (i.e.38 kidneys) were of the uncontrolled (category II) donors. After viability assessment on machine perfusion; two kidneys were discarded due to positive tests for syphilis, four kidneys had high total GST levels, five kidneys due to high IRVR and poor flow characteristics and one did not flush on retrieval. Three kidneys were exported after viability tests. In 28 NHBD kidney recipients, immediate graft function was seen in two kidneys, 22 (84.6%) developed delayed graft function. One kidney had primary non-function, and two recipients lost their grafts, due to chronic rejection and renal vein thrombosis. There were two deaths, unrelated to transplantation. Graft survival was achieved in 88.4% (23/26 graft survival in phase III) of cases.

Conclusion: Machine perfusion and assessment of NHBD kidneys has been successfully introduced to the Newcastle NHBD programme. This approach, using renal transplants from largely category II donors produced a success rate of 88.4% which was significantly better than the phase II period (45.5%) of the program p=0.023, Fisher 2 tail test).
Fungal Treatment of Aspen for Wood Resin Reduction: Effect on Aged Aspen Wood Chips at Room Temperature and at 5°C
Authors: Rocheleau M.-J. , Sitholé B. B. , Allen L. H. , Noël Y.
Published: October 2004

A laboratory evaluation was conducted to study the effectiveness of a biotreatment for deresinating
wood chips from aged aspen. This treatment involves inoculating chips with a fungal inoculum, Cartapip
97® that feeds on wood resin components. This study demonstrated that, at room temperature and at
5°C, Cartapip can colonize chips from aged aspen despite the lower extractives content of the wood.
Fungal treatment resulted in an additional 8% removal of wood resin in treated chips than in untreated
chips after 3 weeks of seasoning. Analysis of the extractives by gas chromatography showed a
significant reduction of steryl esters (25%), which are troublesome non-saponifiable wood resin
components often found in aspen pitch deposits. The fungal treated chips were brighter than the
untreated chips because the fungus prevented colonization of the chips by staining fungi. These results
imply that fungal treatment of aspen chip piles in the winter will reduce the amount of wood resin in
the chips and maintain their brightness. Such treatment will help alleviate pitch deposition problems
attributable to aspen wax and reduce bleaching costs.
Characterization of Lignin-Carbohydrate Fractions Isolated from the Wood Parasite Cistance deserticola Y.C. Ma
Authors: Kosiková B. , Ebringerová A. , Naran R.
Published: October 2004

Chemical analysis of Cistanche deserticola showed the presence of 7.5% of Klason lignin. Different
lignin-carbohydrate fractions have been isolated from the methanol pre-extracted and depectinated
Cistanche drug by sequential extractions using dioxane-water, cold and hot water, and 4% NaOH
solution. 13CNMR spectroscopy in combination with sugar analysis were used to characterize the
isolated fractions. The proportions of the guaiacyl-, syringyl- and p-hydroxyphenyl units in the
lignin-rich fractions differ significantly from those of both hardwood and softwood lignins and
resemble more those of gramineous lignins. The carbohydrate portion consists of xylan, starch, pectic
polysaccharides, and cellulose in proportions which are not typical of wood tissues.
Acid Reactions of Lignin Models of β-5 Type
Authors: Li S. , Lundquist K.
Published: October 2004

Refluxing of trans–2-(3,4-dimethoxyphenyl)-3-hydroxymethyl-7-methoxy-2,3-dihydrobenzo[b]furan
with dioxane-water (9 : 1) in the presence of various acid catalysts led to the formation of 2-(3,4-dimethoxyphenyl)-
7-methoxy-3-methylbenzo[b]furan, the trans and cis forms of 2-hydroxy-3,3′4′-trimethoxystilbene
and cis–2-(3,4-dimethoxyphenyl)-3-hydroxymethyl-7-methoxy-2,3-dihydrobenzo[b]furan.
The proportions of the products were strongly dependent on the particular acid used as catalyst. HCl and
to a greater extent HBr favored the formation of the 2-arylbenzofuran (phenylcoumarone) while the
trans-stilbene derivative predominated in reaction products from the experiments with trifluoromethane
sulfonic acid as the catalyst. Isomerization of the starting material occurred, regardless of the nature of
the catalyst (small amounts of the cis-isomer formed). The number of phenylpropane units in spruce
lignin attached to an adjacent unit by a β−5 linkage was estimated to be 6–9% on the basis of 1H NMR
spectrometric measurements of the formation of phenylcoumarone structures on refluxing of milled wood
lignin from spruce with 0.1M HBr in dioxane-water (9 : 1).
Atmospheric Acetic Acid Pulping of Rice Straw II: Behavior of Ash and Silica in Rice Straw during Atmospheric Acetic Acid Pulping and Bleaching
Authors: Pan X.-J. , Sano Y. , Ito T.
Published: October 2004

A detailed examination was made of the behavior and distribution of ash and silica during
atmospheric acetic acid pulping and subsequent bleaching of rice straw. Ash-rich pulps (in unbleached
pulp, about 18%; and in bleached pulp, 16%) with matchable strength properties for conventional
alkaline pulps were obtained from rice straw by acetic acid pulping. More than 50% of the ash and
about 75% of the silica in rice straw were retained in the pulp after pulping. Because only those
acid-soluble mineral components were dissolved during acetic acid pulping, the ash remained in the
pulp consisted mainly of silica (92.9% of the ash in unbleached pulp and 97.3% of the ash in
bleached pulp). Although part of the ash dissolved during bleaching, the ash content of bleached pulp
was still 15.5%, a value much higher than that in other conventional pulps. This type of ash might
be good as a filler for paper. Fractionation analysis and the profile and mapping of silica by scanning
electron microscope combined with an energy dispersive X-ray analysis (SEM-EDXA) indicated that
the silica in the bleached pulp was located mainly in epidermal cells and not in other elements, such
as fibers and parenchyma, and that the silica-rich epidermal cells were scattered throughout the pulp
as single cells or in bundles.
Non-Darcian Air Flow in Wood. Part 3. Molecular Slip Flow
Authors: Lu J. , Avramidis S.
Published: October 2004

In this study, the detection and evaluation of non-Darcian air flow due to slip flow through four species
were carried out. The results indicated that non-Darcian air flow due to slip flow existed in all the
specimen groups studied. The true permeability of red oak heartwood, red alder heartwood, ponderosa
pine sapwood and Douglas-fir sapwood was 20.91, 7.05, 0.51 and 0.068μ3/μm, respectively. The
average ratios of the superficial specific permeability at 50kPa mean pressure to the true permeability
were found to be: 1.047 for red oak heartwood; 1.204 for red alder heartwood; 1.292 for ponderosa
pine sapwood; and, 1.53 for Douglas-fir sapwood. The slip flow constant b was highest (26.5kPa) for
Douglas-fir sapwood, followed by that for ponderosa pine sapwood (14.6 kPa) and red alder heartwood
(10.2 kPa), and lowest (2.3kPa) for red oak heartwood. The radius (r) and the number of average
effective openings (n) were found to be: 17.432μm and 0.066×106 per cm2 for red oak heartwood;
3.955 μm and 7.5 ×106 percm2 for red alder heartwood; 2.972μm and 3.3 ×106 percm2 for ponderosa
pine sapwood; and, 1.552μm and 3.6 ×106 per cm2 for Douglas-fir sapwood respectively.
Laser Ablation of Machined Wood Surfaces. 1. Effect on End-Grain Gluing of Pine (Pinus silvestris L.) and Spruce (Picea abies Karst.)
Authors: Stehr M. , Seltman J. , Johansson I.
Published: October 2004

This report describes two attempts to test the effect of removing the layer of damaged cells—the
mechanical weak boundary layer. In both trials, the wood has been laser ablated using different types
of lasers with different wavelengths.

The goal has been to determine whether the glue joint strength is influenced by the mechanical weak
boundary layer and to show how the laser wavelength affects the glue joint strength. The statistical
evaluation of the results shows however no great differences between glue joints made of ablated
and glue joints made of unablated surfaces. Nor are there any real differences between the different
lasers and different wavelengths. This may be because there are indeed no differences between
ablated and unablated surfaces, in terms of a mechanical weak boundary layer, but it may also be
due to cracks which occurred in the wood specimens, and it is also possible that the glue itself was
too weak. An ESEM (Environmental Scanning Electron Microscope)—analysis showed that fracture
occurred primarily in the glueline and not in the boundary layer. In addition to the ESEM analysis
and the statistical evaluation, a theoretical FEM (Finite Element Method)—analysis has been used to
explain the crack initiation in the second trial.
A Study of Ordinary Portland Cement Hydration With Wood by Isothermal Calorimetry
Authors: Sauvat N. , Sell R. , Mougel E. , Zoulalian A.
Published: October 2004

As an essential preliminary to understand the hydration of wood-cement composites, the effects of some
additives on the delayed setting due to wood of an Ordinary Portland Cement have been investigated
by isothermal calorimetry. With the addition of calcium chloride and activated charcoal, an increase of
50% of the total enthalpy is observed in wood-cement composites hydration, because calcium chloride
mostly influences aluminate phases and activated charcoal silicate phases.
Extraction Conditions Affect Protein Recovery and Enzyme Activity in Wood Wafers Exposed to Stain Fungi and Bioprotectants
Authors: Li C. , Morrell J. J.
Published: October 2004

We investigated the ability of selected buffers to extract proteins and other materials from the
surfaces and subsurfaces of ponderosa pine wafers colonized by selected wood stain fungi and
potential bioprotectant bacteria. The effects of extraction conditions on enzyme activity were also
analyzed. The addition of Tween 80 to the extraction media markedly enhanced total protein recovery
as well as enzyme activity. Increasing the extraction time from 6 to 12 hours failed to increase total
protein recovery, indicating that either most of the protein was removed earlier or proteases in the
wood had attacked proteins liberated during extraction. Relatively short extractions using sodium
acetate buffer amended with Tween 80, therefore, produced the best protein recovery and enzyme
activity. These conditions can be used for extracting wood colonized by various combinations of stain
fungi and bacterial bioprotectants to study the effects of the interaction on physiologic activities of
the target fungi.
Development of Model Systems for Investigations of the Dry Rot Fungus Serpula lacrymans (Schumach. ex Fr.) Gray: Use for Analysis of the Environmental Sensitivity of the Organism
Authors: Low G.A. , Palfreyman J. W. , White N. A. , Sinclair D. C. R.
Published: October 2004

Novel microcosms were used to test separately the effects of aeration and humidity on the decay
capacity, linear spread and survival of the dry rot fungus Serpula lacrymans. The application of a
pumped air supply resulted in cessation of fungal activity in the microcosms at all but the lowest air
flow rate. At this lowest rate marked growth tropisms were sometimes seen and linear growth of the
fungus away from the air supply was accentuated. In both air flow and humidity experiments the loss
of growth and decay capabilities was not always accompanied by a loss of viability. Larger scale growth
chambers incorporating simulated flooring and plaster walling were developed in sealed aquarium tanks
using both new and old building materials. Differences in growth rates and morphology of S. lacrymans
were noted, with old materials generally being more favorable to the growth of the organism. Opening
the growth chambers and applying a controlled air flow rapidly halted the spread of S. lacrymans
resulting in the fungal mycelium shrivelling, discolouring and becoming susceptible to attack by moulds.
Loss of viability of S. lacrymans in re-sealed chambers depended crucially on the instigation of a
water-deprivation schedule. The results may have serious implications for the use of purely environmental
strategies for the remedial treatment of outbreaks of the dry rot fungus in buildings.
Water Repellent Efficiency of Organic Solvent Extractives from Aleppo Pine Leaves and Bark Applied to Wood
Authors: Passialis Costas N. , Voulgaridis Elias V.
Published: October 2004

Natural wax-like materials were extracted from leaves and bark of Aleppo pine (Pinus halepensis Mill.)
by using toluene as organic solvent. Experimental water repellent formulations (WRFs) were prepared
using 10% gum rosin as the resin constituent and 0%, 1% and 2% paraffin wax, pine needle/bark
extracts or mixtures of paraffin wax and needle/bark extracts in proportion 1 : 1 as hydrophobic
substance. All experimental WRFs applied to small, cross-sectional wood specimens of Scots pine
(Pinus sylvestris L.) and beech (Fagus sylvatica L.). Wood specimens were impregnated by a simple
immersion technique and the water repellent effectiveness (WRE) was assessed by using tangential
swelling data. Toluene soluble extracts from needles and bark applied to wood provided hydrophobic
properties to pine and beech wood specimens but to a lesser degree when compared to paraffin wax.
Bark extracts appeared to be stronger hydrophobic materials than needle extracts. Both needle and bark
extracts can be successful substitutes for paraffin wax in WRFs up to 50 %. The degree of protection
provided by WRFs and the differences between treatments were smaller in pine heartwood and beech
sapwood than in pine sapwood.
Structural Characterization of Cork Lignin by Thioacidolysis and Permanganate Oxidation
Authors: Marques A.V. , Pereira H. , Meier D. , Faix O.
Published: October 2004

Quercus suber L. milled cork lignins obtained from extractive-free cork (MCL) and from saponified
cork (MCLsap) were characterized by thioacidolysis and KMnO4 oxidation. These techniques and the
previously used analytical pyrolysis revealed that cork contains a guaiacyl lignin (G lignin) with
94–96% guaiacyl-, ca. 3% syringyl-, and 2–3% of 4-hydroxyphenyl-propane units. The total yields
of degradation products in thioacidolysis and KMnO4 oxidation experiments were lower in comparison
to those of a spruce milled wood lignin (MWLspruce) suggesting a higher cross-linking in the G-lignin
of cork. The higher frequency of “condensed” structures (having C-C or C-O-C linkages to aromatic
rings) in cork lignin was also manifested in the relative abundance of various aromatic acids obtained
by KMnO4 oxidation. The cork lignin (MCLsap) contains only low amounts (ca. 2%) of covalently
bonded suberinic acids. Numerous free aliphatic suberinic acids were detected and identified in the ether
soluble part of MCLsap. Ferulic acid was not liberated by thioacidolysis, pointing at an in situ acylation.
We suggest that the major part of the aromatic domain in cork is a G-lignin but that it includes also
another structural moiety with higher H-unit content and linked by thioacidolysis resistant bonds.
The Reaction of Phenolic Model Compounds in the Laccase-Mediator System (LMS) Investigations by Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS)
Authors: Potthast A. , Rosenau T. , Koch H. , Fischer K.
Published: October 2004

Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to investigate the reaction products obtained by treatment of phenolic substances with the laccase-mediator system, consisting of the enzyme laccase and a low-molecular-weight substance, the so-called mediator.

Two mediators, 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid diammonium salt (ABTS) and 1-hydroxybenzotriazole (HOBT), were employed. Polymerizing and depolymerizing properties of the LMS were investigated and assigned to specific components of the system,i. e., laccase and mediator. The polymerizing action of laccase and the ABTS cation radical on phenols was demonstrated in addition to the depolymerizing effect of the LMS. The LMS causes polymerization of phenolic substrates in the initial phase of the reaction, but then degrades the initially formed polymers. The extensive breakdown of this oligomeric and polymeric material occurs exclusively in the presence of both components, mediator and laccase. Furthermore, it is also dependent on the type of polymer formed.
Surface Composition and Morphology of CTMP Fibers
Authors: Börås Linda , Gatenholm Paul
Published: October 2004

The aim of this study was to investigate the surface composition and morphology of Chemithermomechanical
pulp (CTMP) fibers from spruce. The fibers were exposed to a sequence of mild
treatments such as washing, peroxide bleaching and extraction. The effects of treatments on fiber
bulk composition and surface properties were investigated. All treatments did not significantly result
in changes in total lignin and carbohydrate content. However, the extractives were stepwise
removed. With the Electron Spectroscopy for Chemical Analysis (ESCA) technique, a gradual
reduction of unoxidized carbon in the C1s resolved peak was shown, which was correlated to the
removal of non-carbohydrates. Variations in surface topography among the analyzed samples were
displayed with Atomic Force Microscopy (AFM) imaging of fibers in tapping mode. The wetting
properties of all pulps were measured by Dynamic Contact Angle (DCA) on the single fibers. The
advancing contact angle decreased and the hysteresis is also reduced, as a result of treatments.
ESCA, AFM and contact angle analyses suggest that the extractives are distributed as globular
particles at the fiber surface. Phase imaging AFM indicated the presence of lignin as irregular
patches at the surface. A model of the CTMP fiber surface based on experimental findings in this
work is proposed.
Influence of Growth Rate and Cambial Age on Density of Rauli (Nothofagus nervosa) in Relation to Vessel Lumen Areas and Numbers
Authors: Denne M. P. , Cahalan C. M. , Aebischer D. P.
Published: October 2004

To assess the likely effects of silvicultural treatment on the wood quality of Nothofagus nervosa grown
in the UK, and the possibilities of independent selection within seed origins for density and growth
rate, ring width and wood density were analysed from pith to bark of 19 trees. Variations in vessel
lumen size, vessel number mm−2, and total lumen area mm−2 were analysed in ten trees. Since density
increased by only 0.005g cm−3 per mm increase in ring width, silvicultural practices such as initial
spacing and thinning are not likely to have a substantial effect on the wood density of rauli. Similarly,
variation in density with cambial age was significant but relatively minor in the 40- and 60-year old
trees of the present sample, suggesting that the rotation length is unlikely to have any practical influence
on the density of rauli. Considerable between-tree differences in density were found which did not
correspond to differences in ring width, suggesting it should be feasible to select independently for
density and growth rate. These differences in density were associated with differences in both vessel
lumen size and vessel number mm−2
Convective Mass Transfer Coefficient at Wooden Surface in Jet Drying of Veneer
Authors: Hukka Antti , Oksanen Olli
Published: October 2004

The relationship between heat and mass transfer at wooden surface is investigated experimentally by
drying 1.6 mm thick birch veneers in constant conditions in a laboratory-scale roller dryer. By
intermediate weighing of the samples a drying curve is established for each specimen. The drying curves
are formulated in a functional form to produce the drying rate as a function of wood moisture content.
Based on that and the measured heat-transfer coefficient a correction factor is calculated for the mass
transfer coefficient predicted by the boundary layer theory.

The results show that the convective mass transfer coefficient for wooden surfaces substantially deviates
from that given by the analogy between heat and mass transfer. The correction factor describing the
internal resistance for evaporation is strongly dependent on wood temperature within the range
50–90°C, but for practical purposes not dependent on the average moisture content of the veneer (range
40–70%). The numerical value of the correction coefficient established is somewhat lower than
published earlier by other researchers.
Tangential Youngs Modulus of Coniferous Early Wood Investigated Using Cell Models
Authors: Watanabe Ugai , Norimoto Misato , Ohgama Toshimasa , Fujita Minoru
Published: October 2004

The relationship between the tangential Young's modulus and the transverse cell shape in coniferous
early wood was investigated by using cell models constructed by power spectrum analysis. The
calculated Young's moduli of the cell models explained qualitatively the change of the experimental
Young's moduli with density as well as the difference in the experimental values among species. The
calculated Young's moduli differed significantly among species depending on the cell model shapes
when compared at the same density. With increasing element angle in the model, the Young's modulus
greatly increased without a significant change in the density, especially at the larger ratios of the axial
length of the tangential cell wall to that of the radial cell wall.
Effects of Heat Treatments of Wood on the Feeding Behaviour of Two Subterranean Termites
Authors: Doi S. , Kurimoto Y. , Ohmura W. , Ohara S. , Aoyama M. , Yoshimura T.
Published: October 2004

This paper deals with the results of choice feeding tests of two termite species, Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe), with steam-treated and dry-heated samples of Japanese commercial woods. Some steam-treated species were heavily attacked by C. formosanus and R. speratus while all dry-heated samples were attacked not more than unheated controls except for the combination Japanese larch-R. speratus. The steam treatment in some wood species produced feeding attractants which were removed by hot water extraction. Termite species showed some differences in the susceptibility to these substances. Attraction of the termites to steam-treated Japanese beech was different from that to the steam-treated softwoods. These phenomena were discussed with references to heat treatment of wood as well as to termite attractive factors.
The Resistance of Wood Chemically Modified with Isocyanates. Part 1. Brown Rot, White Rot and Acid Chlorite Delignification
Authors: Williams F. Cardias , Hale M.D.
Published: October 2004

This study was to assess the bioprotectant performance of chemical modification with three different isocyanates (n-butyl, hexyl and 1,6-diisocyanatohexane, BuNCO, HeNCO and HDI respectively) in Corsican pine (Pinus nigra Schneid) sapwood. Wood-isocyanate bond formation was verified by the increase in sample weight, volume and by infra-red spectroscopy.

Basidiomycete (Coniophora puteana, Gloeophyllum trabeum, Coriolus versicolor, Pycnoporus sanguineus) decay tests demonstrated protection by chemical modification. The relationships of fungal species, weight percent gain (WPG), and decay induced weight loss were examined. One of the brown rot fungi, C. puteana, showed higher threshold protection values than the other fungi tested and the diisocyanate showed better performance.

Chemical characteristics of the sound and brown rotted wood (C. puteana) have been examined using sulphuric acid and sodium chlorite procedures to clarify the principles which govern isocyanate modifications and restrict fungal decay. These demonstrated that appreciable wood protection against C. puteana only occurred when the holocellulose fraction showed substantial changes due to chemical modification.
Effect of IPBC/DDAC on Spore Germination and Hyphal Growth of the Sapstaining Fungus Ophiostoma piceae
Authors: Xiao Y. , Kreber B.
Published: October 2004

Fungicide interactions were investigated using Ophiostoma piceae (Münch) H. and P. Syd, unseasoned radiata pine (Pinus radiata D. Don) and an antisapstain formulation based on 3-iodo-2-propynyl butyl carbamate (IPBC) and didecyl dimethyl ammonium chloride (DDAC). Treated and untreated wood samples were inoculated with O. piceae and then periodically examined over an incubation period of one month using light microscopy and scanning electron microscopy. Additional treated and infected wafers were removed after 8 and 15 days, rinsed with distilled, sterile water and then further incubated on malt agar nutrient media before examining microscopically.

The results of the study showed that prolific spore germination and mycelial growth of O. piceae occurred on untreated radiata pine within 24 hours whereas the majority of spores did not germinate on treated wood. However, in some spores the process of germination was only delayed, occurring after 20 days of incubation. Furthermore, it was noticed that once spore germination occurred hyphae rapidly colonised treated wafers possibly indicating that mycelium of O. piceae is more tolerant to IPBC/DDAC treatment, than spores. The possible mode of action of IPBC/DDAC on spores and mycelium of O. piceae is discussed.
Biodegradability of Extractives in Sapwood and Heartwood from Scots Pine by Sapstain and White-Rot Fungi
Authors: Martínez-Inigo M.J. , Immerzeel P. , Gutierrez A. , Río J.C. del , Sierra-Alvarez R.
Published: October 2004

The fungal degradation of lipophilic extractives in sapwood and heartwood from Scots pine (Pinus sylvestris) was studied. In sapwood, the white rot fungi,Bjerkanderasp. andFunalia trogii, removed higher amounts of extractives than the sapstain strains,Ophiostoma ainoaeandCeratocystis allantospora. Triglycerides, long chain fatty acids, steryl esters and waxes in pine sapwood were almost completely degraded by all the fungi. Sterols and resin acids were also extensively degraded by the white rot strains; however, these components were not or only poorly removed by the sapstain fungi. The removal of total extractives by all the fungal strains was higher in sapwood as compared to heartwood. The highly concentrated extractive fraction in pine heartwood mainly consists of resin acids. As observed in sapwood, sapstain were also poorly effective in the degradation of the resin acids present in heartwood. The fungal degradation of heartwood extractives was not only limited by the degradative ability of the various test microorganisms, but also by the inhibitory effect exerted by the extractive fraction. The white rot fungusF. trogiiwas particularly inhibited on heartwood.Bjerkanderasp. showed a higher tolerance to toxic extractives and was the most efficient fungus in degrading extractive constituents in both Scots pine heartwood and sapwood. Therefore,Bjerkanderasp. strain BOS55 should be considered as a potential agent for pitch control in pulp and paper manufacture.
Fractional Isolation and Characterization of Polysaccharides from Oil Palm Trunk and Empty Fruit Bunch Fibres
Authors: Sun R. , Fang J.M. , Mott L. , Bolton J.
Published: October 2004

The polysaccharides in oil palm trunk fibre and empty fruit bunch (EFB) fibre were fractionated into cold water solubles, hot water solubles, 1% NaOH solubles, and 17.5% NaOH soluble fractions. Cellulose (approximately 42%) and hemicelluloses (approximately 33%) were the major polysaccharides in the palm trunk fibre and EFB fibre. Extractions of the lignified fibres with cold water, hot water, and 1% NaOH produced the hemicellulosic fractions, which were enriched in xylose and glucose and to a lesser extent, arabinose-, galactose-, mannose-, rhamnose-, and ribose-containing polysaccharides, together with noticeable amounts of associated lignin (4.5–31.2%). Further extraction of the delignified fibre residues with aqueous 17.5% NaOH removed the hemicellulosic fractions, which were strongly enriched in xylose-containing polysaccharides and relatively free of associated lignin (0.3–0.7%). Eight phenolic acids and aldehydes, including p-hydroxybenzoic acid, p-hydroxybenzaldehyde, vanillic acid, syringic acid, vanillin, syringaldehyde, p-coumaric acid, and ferulic acid, were detected in the mixtures of alkaline nitrobenzene oxidation of associated lignin in all the sixteen polysaccharide fractions. The results obtained showed that hemicelluloses in the cell walls of oil palm trunk and EFB fibres, are mainly bonded with lignin by syringyl units.
Chemical Modification of Wood with Perfluoralkyl Ethanol and 4,4'-Diphenylmethane Diisocyanate
Authors: Engonga P. Edou , Schneider R. , Gérardin P. , Loubinoux B.
Published: October 2004

Grafting of perfluoroalkyl ethanol derivatives on spruce meal (Picea abies) and beech blocks (Fagus sylvatica) was performed using 4,4′-diphenylmethane diisocyanate (MDI). The formation of urethane bonds between MDI, perfluoroalkyl ethanol and wood allowed to increase wood's dimensional stability. Contact angle measurements were also performed. θ values obtained for wood grafted with perfluoroalkyl ethanol derivatives were greater and did not decrease with time compared to those obtained with unmodified wood.
Radical Formation in Ozone Reactions with Lignin and Carbohydrate Model Compounds
Authors: Ragnar M. , Eriksson T. , Reitberger T.
Published: October 2004

Using different independent methods, the kinetics of ozone consumption and the initial radical yield in reactions of ozone with lignin and carbohydrate model compounds were investigated. It was demonstrated that ozone reacts with phenolates several orders of magnitude more rapidly than with corresponding undissociated phenols. The pH dependence of the radical yield does not completely follow the pK
a-value of the phenols. In fact, the radical yield starts to increase at pH 3 for all the phenolic model compounds investigated. Several indications suggest that superoxide rather than the hydroxyl radical is initially formed when ozone reacts with lignin model compounds. In contrast to lignin model compounds no radicals were detected in ozone reactions with carbohydrate model compounds or olefins. On the basis of this study, it may be concluded that ozone bleaching should preferably be performed at pH 3 and at a higher consistency. No significant effect of metal ions was observed.
Cement Hydration Tests Using Wood Flour may not Predict the Suitability of Acacia mangium and Eucalyptus pellita for the Manufacture of Wood-Wool Cement Boards
Authors: Semple K.E. , Cunningham R.B. , Evans P.D.
Published: October 2004

Wood-wool cement boards (WWCBs) are manufactured in many tropical countries which have extensive eucalypt and acacia plantations. Wood from such plantations could act as a potential raw material for WWCBs, but the suitability of most tropical eucalypts and acacias for the manufacture of such products is unknown. This study was undertaken to assess whether the standard laboratory test for wood-cement compatibility, which measures heat of hydration in wood flour-cement mixtures, is an appropriate method for screening tropical eucalypts and acacias for their compatibility with cement and suitability for the manufacture of WWCBs. Wood samples from a tropical eucalypt (E. pellita) and a tropical acacia (A. mangium) were tested in two forms, i. e. flour and wool, for their compatibility (expressed by maximum hydration temperature and CA-factor) with Portland cement. Form significantly influenced the effect of the wood on cement hydration, resulting in a different species compatibility ranking for flour and wool. As the heartwood content of wood-wool-cement hydration test samples increased, Tmax. and CA factor increased whereas the opposite occured for those containing wood flour. Tests using wood flour ranked E. pellita as being more compatible with cement than A. mangium whereas the ranking was reversed when wood-wool was used. Furthermore at low wood levels the compatibility of samples containing wood-wool or wood flour with cement was similar whereas at high wood levels, samples containing wood-wool were much more compatible with cement than those containing wood flour. Laboratory tests designed to screen eucalypts and acacias for their compatibility with cement should use wood in a coarser form with a lower surface-to-volume ratio than flour. Caution should be exercised if using results from wood flour-cement hydration tests to estimate the suitability of wood species for the manufacture of WWCBs and possibly other wood-cement composites.
Modifications of Hybrid Walnut (Juglans nigra 23 x Juglans regia) Wood Colour and Phenolic Composition Under Various Steaming Conditions
Authors: Burtin Patricia , Jay-Allemand Christian , Charpentier Jean-Paul , Janin Gérard
Published: October 2004

The effects of steaming were studied on Walnut wood from a hybrid (Juglans nigra 23 × J. regia) tree
in terms of wood colour and phenolic composition. Wood samples were subjected to treatments at 75,
100 and 125°C for 4, 8, 16 and 24 hours. Colour changes were measured in the CIELCh colour system
and phenolics were characterized and quantified by means of HPLC. Steaming mainly resulted in a darkening
of wood tissues. Colour changes increased as temperature increased from 75 to 125°C. Lightness
L* gradually decreased from 0 to 24 h at 75°C, whereas with higher temperatures, most of the darkening
occurred within the first 4 hours of exposure. Contrast in colour, between sapwood and heartwood
in particular, could be reduced by steaming at 125°C. The best steaming treatment, leading to a colour
of steamed sapwood close to that of natural heartwood, was at 100°C/16 h. Hydrojuglone glucoside
(HJG), ellagic and gallic acid derivatives (E1, E2 and G respectively) were gradually degraded by steaming,
whereas a new flavonol (F) and oxidation products (OP) increased. Relationships between wood
colour and phenolic content are discussed.
Modelling the Moisture Induced Risk of Decay for Treated and Untreated Wood Above Ground
Authors: Rapp A. O. , Peek R.-D. , Sailer M.
Published: October 2004

During two years of natural weathering the course of the moisture content of test samples of pine sapwood
(Pinus sylvestris L.), Norway spruce (Picea abies L.), oak heartwood (Quercus robur L.) and Douglas
fir heartwood (Pseudotsuga menziesii Franco.) was recorded by means of 12,000 individual gravimetric
readings. The samples were untreated, treated with a weather protection varnish, or impregnated
with melamine resin. The data were evaluated with regard to the number of days per year on which the
moisture content of wood exceeded the limit of 25%. From the results of subsequent laboratory investigations
into the adsorption of liquid water and moisture vapour desorption using the same test material,
it was possible to work out a mathematical relationship (MRI = moisture induced risk index) which
correlates closely with the number of days of more than 25% moisture content during the second year
of natural weathering. The MRI is proposed as a parameter for the assessment of the protective effect of
wood treatments which are intended to reduce moisture content and also for durability prediction of
untreated wood in out of ground contact situations.
A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 1. The Reaction of Coniferaldehyde Model Compounds
Authors: Pan George X. , Spencer Liam , Leary Gordon J.
Published: October 2004

The reactions of chromophoric model compounds of the coniferaldehyde type with hydrogen peroxide and
peracetic acid have been investigated in relation to lignin-retaining bleaching. Analysis of the main reaction
products indicated that the side chain of coniferaldehyde could cleave either between the α, β double
bond or between the β, γ bond. Comparison of possible reaction pathways to the formation of oxidation
products from hydrogen peroxide and peracetic acid suggested that peracetic acid is more effective than
hydrogen peroxide. Advantages of peracetic acid over hydrogen peroxide include a faster rate of reaction,
more efficient utilization of the bleaching agent and less likelihood of producing new chromophores.
A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 2. The Reaction of Stilbene-Type Model Compounds
Authors: Pan George X. , Spencer Liam , Leary Gordon J.
Published: October 2004

The reactions of three hydroxy- and/or methoxy-substituted stilbenes with hydrogen peroxide and peracetic
acid have been investigated. Overall, the reactivity of stilbenes was greater towards peracetic acid
than towards hydrogen peroxide. Among the stilbene model compounds studied, 4-hydroxystilbene (I)
was virtually unreactive to hydrogen peroxide, but was oxidized by peracetic acid to a varying extent
that was highly pH-dependent. 4,4′-Dihydroxy-3,3′-dimethoxystilbene (II) and 3,5-dimethoxy-4-hydroxystilbene (III) showed a greater reactivity to either hydrogen peroxide or peracetic acid than
4-hydroxystilbene (I).
Dynamics of Hardwood Impregnation
Authors: Costanza Vicente , Miyara Alberto José
Published: October 2004

The phenomenon of axial liquid penetration in hardwoods is modeled through two different mechanisms:
in one of them the driving force is taken to be the empty space that remains unfilled inside the material;
in the other one, it is the pressure differential between the interior of the material and its liquid environment.
The equations obtained show an increase of liquid retention exponentially approaching an asymptote,
which agrees with experimental results. By combining them with existing models for liquid permeability,
an equation is obtained for predicting retention as a function of wood ultrastructure for a given
liquid under fixed conditions.
Neurotrophin-3 Reverses Chronic Mechanical Hyperalgesia Induced by Intramuscular Acid Injection
Authors: Gandhi Rohan , Ryals Janelle M. , Wright Douglas E.
Published: October 2004

Injection of acid into the gastrocnemius muscle results in a persistent, mechanical hyperalgesia of the hindpaw (Sluka et al., 2001). Here, the ability of neurotrophins to alter the development of this secondary hyperalgesia was assessed using transgenic mice and exogenous neurotrophin administration. Acid-induced hyperalgesia was measured in wild-type and transgenic mice that overexpress neurotrophin-3 (NT-3) in muscle (myo/NT-3mice). Mechanical and thermal sensitivity of the hindpaws were assessed after injections of acidic saline, pH 4, into the right medial gastrocnemius. Wild-type mice exhibited mechanical but not thermal hyperalgesia in both paws 1 d after acid injection. In contrast,myo/NT-3mice developed a transient mechanical hyperalgesia in both paws that disappeared by 2-3 d. The reversal of hyperalgesia inmyo/NT-3mice could be mimicked by intramuscular administration of exogenous NT-3 to acid-injected mice but not by other neurotrophins. The route of NT-3 administration appears critical, because intrathecal or intraperitoneal delivery were ineffective. The hyperalgesia could only be reversed by NT-3 treatment concurrent with acid injection and not after the emergence of hyperalgesia. The acid-induced hyperalgesia did not redevelop after the termination of NT-3 treatment, suggesting that NT-3 permanently reversed the hyperalgesia. Consistent with the behavioral data, paw palpation of acid-injected mice significantly increased Fos expression in the spinal cord of wild-type but notmyo/NT-3or NT-3-injected mice. The attenuation of hyperalgesia suggests that NT-3 may be a modulator of muscle-derived pain, and NT-3 may suppress events that lead to secondary hyperalgesia triggered by insult to muscle afferents.
Action Potential Backpropagation and Multiglomerular Signaling in the Rat Vomeronasal System
Authors: Ma Jie , Lowe Graeme
Published: October 2004

In the accessory olfactory bulb (AOB), sensory neurons expressing a given vomeronasal receptor (VR) gene send divergent projections to many glomeruli, and second-order neurons (mitral cells) link to multiple glomeruli via branched primary dendrites. We used calcium imaging and paired somadendritic patch-clamp recording to track backpropagated action potentials (APs) in rat AOB primary dendrites. In cells loaded with 150 μmCalcium Orange, somatic spikes elicited fluorescence transients over the entire primary dendritic tree, and the relative fluorescence increment ΔF/F0increased along all branches from soma to glomeruli. Backpropagation was reliant on Na+channels: in 1 μmTTX, somatic AP commands evoked dendritic Ca2+transients that declined steeply with distance. In paired soma- dendritic whole-cell recordings, backpropagated APs were unattenuated up to ∼200 μm from the soma, whereas subthreshold voltage transients decayed markedly. Computational modeling indicated that the large distal Ca2+transients are consistent with active, not passive, backpropagation. Genetic tracing in the AOB has suggested homotypic connectivity with individual mitral cell dendritic arbors projecting only to glomeruli targeted by sensory neurons expressing the same VR gene. Non-decremental, non-dichotomous backpropagation in AOB primary dendrites ensures fast, reliable communication between mitral cells and their homotypic glomeruli, binding them into functional modules in accordance with their VR-coded inputs.
Persistent Accumulation of Calcium/Calmodulin-Dependent Protein Kinase II in Dendritic Spines after Induction of NMDA Receptor-Dependent Chemical Long-Term Potentiation
Authors: Otmakhov Nikolai , Tao-Cheng Jung-Hwa , Carpenter Stephen , Asrican Brent , Dosemeci Ayse , Reese Thomas S. , Lisman John
Published: October 2004

Calcium/calmodulin-dependent protein kinase II (CaMKII) is a leading candidate for a synaptic memory molecule because it is persistently activated after long-term potentiation (LTP) induction and because mutations that block this persistent activity prevent LTP and learning. Previous work showed that synaptic stimulation causes a rapidly reversible translocation of CaMKII to the synaptic region. We have now measured green fluorescent protein (GFP)-CaMKIIα translocation into synaptic spines during NMDA receptor-dependent chemical LTP (cLTP) and find that under these conditions, translocation is persistent. Using red fluorescent protein as a cell morphology marker, we found that there are two components of the persistent accumulation. cLTP produces a persistent increase in spine volume, and some of the increase in GFP-CaMKIIα is secondary to this volume change. In addition, cLTP results in a dramatic increase in the bound fraction of GFP-CaMKIIα in spines. To further study the bound pool, immunogold electron microscopy was used to measure CaMKIIα in the postsynaptic density (PSD), an important regulator of synaptic function. cLTP produced a persistent increase in the PSD-associated pool of CaMKIIα. These results are consistent with the hypothesis that CaMKIIα accumulation at synapses is a memory trace of past synaptic activity.