bluuebunny/crossref_metadata_2025 huggingface dataset:
The Erythro/Threo Ratio of β-O-4 Structures as an Important Structural Characteristic of Lignin. Part 2. Changes in Erythro/Threo (E/T) Ratio of β-O-4 Structures during Delignification Reactions
Authors: Sugimoto T. , Akiyama T. , Matsumoto Y. , Meshitsuka G.
Published: September 2004

The ozonation method was applied to an analysis of the changes in erythro and threo (E/T) ratio of arylglycerol-β-aryl ether (β-O-4) structures in the residual lignins of delignified wood samples. When delignified by alkali cook, not only the total yield of erythronic and threonic acids per lignin decreased, but also the E/T ratio decreased with the progress of delignification. These results indicate that residual lignin of alkali-delignified wood contain only a small amount of arylglycerol-β-aryl ether structures and/or glycerol side chains, which are relatively rich in the threo form. A suggested reason for this, in addition to the stereo-preferential degradation of the erythroβ-O-4 structure, is the increasing contribution of topologically-inert lignin and/or chemically-inert lignin structures with a low original E/T ratio. In contrast, when the wood samples are delignified by NaClO2 treatment, no significant change is observed in the E/T ratio. This confirms that the NaClO2 delignification proceeds without the residual lignin retaining special configurational characteristics in its side chains.
Industrial Kiln Drying and its Effect on Microstructure, Impregnation and Properties of Scots Pine Timber Impregnated for Above Ground Use. Part 1. Effects of Initial, Final Dryings and Preservative on Impregnation and Timber Quality
Authors: Terziev N.
Published: September 2004

Scots pine (Pinus sylvestris L.) planks were dried in industrial progressive, conventional batch and high temperature kilns. The quality of drying was assessed by measuring the final moisture content and its gradient, deformations, checks and internal stress of planks. The timber was rearranged in three charges and impregnated in an industrial autoclave with copper-based preservatives for above ground use (class AB):Kemwood ACQ 1900, Tanalith E and Wolmanit CX-8. The moisture content was determined after impregnation and the planks were divided into two charges; the first was dried in an industrial conventional batch kiln while the second was air dried. Assessment of the final product quality after kiln and air drying was carried out as after the initial drying. The penetration of preservatives was measured as well. The data were analysed by a statistical mixed model to ascertain the effects of drying and preservatives on the impregnation and timber quality.

A strong relationship was found between the initial drying of Scots pine timber and its quality after impregnation and drying. The conventional batch and high temperature kiln drying ensured similar drying quality regarding the final moisture content and gradient, bow, twist and checks, but the high temperature drying provided significantly better (94.4%of the total sapwood area) penetration of the preservatives tested. It is suggested that changes in wood structure could be provoked during the high temperature drying, thus improving the subsequent impregnation and secondary drying. The progressive and conventional batch kiln drying led to similar penetration of the preservatives; the conventional batch kiln drying ensured significantly lower final moisture content, less twist and surface checks of the timber than the progressive kiln drying. Wolmanit CX-8 penetrated significantly better into the pine sapwood (96.3%) than Kemwood ACQ 1900 and Tanalith E (83.5 and 88.5%, respectively). The planks impregnated with Wolmanit CX-8 achieved the best quality regarding the final moisture content, its gradient and cup. The planks impregnated with Kemwood ACQ 1900 and Tanalith E showed similar quality regarding the penetration and some deformations after drying, but Kemwood ACQ 1900 impregnated planks had highest moisture content and gradient.
Industrial Kiln Drying and its Effect on Microstructure, Impregnation and Properties of Scots Pine Timber Impregnated for Above Ground Use. Part 2. Effect of Drying on Microstructure and Some Mechanical Properties of Scots Pine Wood
Authors: Terziev N. , Daniel G.
Published: September 2004

Scots pine (Pinus sylvestris L.) planks were dried in industrial progressive, conventional batch and high temperature kilns. The timber was further impregnated in an industrial autoclave with three preservatives used for above ground use. Samples dried by the three test methods and control samples were thereafter processed for scanning electron microscopy observations. Small clear specimens were sawn for determination of impact bending strength, modulus of elasticity and rupture (MOE and MOR) and hardness. The high temperature dried wood (at 115 °C) was characterised by partially damaged apertures in some bordered pits and nano- (10–20 nm) and micro checks (1–2 μm) in the warty and S3 layers of the cell walls. It is probable that certain modifications in the structure of the wood polymer complex also occurred due to hemicellulose thermal degradation. The above-mentioned structural changes facilitated the penetration of the preservative during impregnation and its evacuation during the final stage of vacuum. The industrial progressive and conventional batch kiln drying had no visible effect on the microstructure of Scots pine wood. There was no critical reduction of the impact bending strength, hardness and MOE of the dried untreated wood regardless of the drying method. MOR was significantly decreased after the conventional kiln drying, but not following high temperature drying. Impregnation with Tanalith E and conventional batch kiln drying aggravated the MOE and MOR of the high temperature dried wood, but both MOE and MOR did not differ significantly from those of progressive and conventional batch kiln dried samples.
Effect of Growth Rate on Fibre Characteristics in Norway Spruce (Picea abies (L.) Karst.)
Authors: Mäkinen H. , Saranpää P. , Linder S.
Published: September 2004

To study the effect of growth rate on fibre characteristics and their variations in Norway spruce,
trees were sampled in a nutrient optimisation experiment in northern Sweden. Data was collected
from 24 trees (40 years old) from fertilised and control plots after 12 years of annual nutrient application,
as well as from older trees outside the experimental area. Fibre length, fibre diameter,
cell wall thickness, lumen diameter and cell wall percentage were measured from every third annual
ring at breast height and at a height of 4 m. Fibre properties, as well as their standard deviation,
were closely related to ring number and distance from the pith. Intra-ring variation of fibre
characteristics was high compared to their variation between trees. Fertilisation reduced fibre
length and cell wall thickness, but increased fibre and lumen diameter in rings of the same age.
The difference in fibre width, cell wall thickness and lumen diameter between fertilised and control
trees was less apparent, but a greater difference in fibre length was found between the treatments
with regard to distance from the pith. There was a similar effect of fertilisation on fibre
properties in early- and latewood. The effect of enhanced growth rate was less pronounced at a
height of 4 m (near the pith) than at breast height (in older rings). It was demonstrated that it is
possible to model intra-tree variability of fibre characteristics using ring width and cambial age as
independent variables. Models presented are, however, limited by the relatively young age of the
sample trees used.
Techniques for Measuring Growth Stress on the Xylem Surface Using Strain and Dial Gauges
Authors: Yoshida M. , Okuyama: T.
Published: September 2004

Growth stress (growth strain) in trees is usually evaluated using either a strain gauge or a dial
gauge to measure the strain release. We summarize the techniques used to assess growth stress and
compare the two methods. The dial gauge method measures change in distance between two pin
targets when growth stress is released by sawing two grooves; from this the strain released is calculated.
The absolute values of the strain released depended on whether the two grooves were sawn
inside or outside the pin targets: the values in the first case were approximately twice those in the
latter. If the grooves were sawn outside the pin targets, the values for the strain released were
about the same as with the strain gauge method, in which the strain released by sawing a groove at
each end of a strain gauge is measured. The released strain values were consistent when the strain
gauge was glued to the outer surface of the secondary xylem after first fully removing the differentiating
xylem. To release most of the surface growth stress and maximize released strain values, the
optimal distance between the ends of the strain gauge and the grooves cut to release the growth
stress was 3 to 5 mm, and the optimal depth of the groove was 5 to 10 mm. Most of the growth
stress was released immediately when the grooves were sawn.
Surface Roughness and Color Change of Copper-Amine Treated Red Maple (Acer rubrum) Exposed to Artificial Ultraviolet Light
Authors: Kamdem D. P. , Grelier: S.
Published: September 2004

UV absorbers were microwave-grafted onto copper-amine (Cu-MEA) treated maple. The so-treated
wood was weathered with UV light for various periods of time. Two weathering cycles
were used: one with only an irradiation step using a 175W medium pressure mercury lamp of
wavelength higher than 300 nm and a second with irradiation and a water spray step. The surface
color and the surface roughness were monitored and the biological performance of the UV absorbers
grafted on copper amine-treated maple evaluated as well. ∆E, the total color change was
measured and it increased from 0 to 14.7 after 317 h weathering for untreated maple. For Cu-MEA
treated and UV absorbers grafted on the surface, the values of ∆E range from 0.7 to 5.7. The higher
values of ∆E for both treated and untreated samples were associated with the weathering cycle
with the water spray step, suggesting that water plays an important role in the wood discoloration.
However, the microwave grafting of UV absorber on Cu-MEA treated maple did not prevent or
reduce the formation of rough surface or inhibit the biological performance of Cu-MEA. This laboratory
study indicates that phenolic UV absorbers can be microwave grafted on maple to improve
the color stability.
Differences in Resin Acid Concentration between Brown-Rot Resistant and Susceptible Scots Pine Heartwood
Authors: Harju A. M. , Kainulainen P. , Venäläinen M. , Tiitta M. , Viitanen H.
Published: September 2004

The concentration of individual resin acids and the equilibrium moisture content at a relative humidity
of 100% were studied in brown-rot resistant and susceptible Scots pine (Pinus sylvestris L.)
heartwood. About 90% of the resin acids in the heartwood were of the abietane type, abietic acid
being the most abundant. The concentration of resin acids was higher in the decay-resistant heartwood
than in the decay-susceptible heartwood. Resin acids are presumably in part responsible for
the decay resistance of Scots pine heartwood. However, no clear relationship was found between
the concentration of resin acids and the equilibrium moisture content. The role of resin acids may
also be ascribed to mechanisms other than their hydrophobic properties alone. The reasons for the
slight differences in moisture content between the decay classes require further study.
Antioxidant Activity of Abietane-Type Diterpenes from Heartwood of Taiwania cryptomerioides Hayata
Authors: Wang S.-Y. , Wu J.-H. , Shyur L.-F. , Kuo Y.-H. , Chang S.-T.
Published: September 2004

Nine abietane-type diterpenes were isolated from the heartwood of Taiwania cryptomerioides and
their structures identified by spectral analyses. Among these nine compounds, six diterpenes were
isolated for the first time from T. cryptomerioides, including 6,7-dehydroferruginol, 6α-hydroxysugiol,
5,6-dehydro-6-hydroxysugiol, 11-hydroxyferruginol, secoabietane dialdehyde and isohinokiol.
We suggest that abietane-type diterpenes are the dominant diterpenes in the heartwood of T.
cryptomerioides. A possible biosynthesis pathway is proposed. In addition, a 1,1-diphenyl-2-picrylhydrazyl
(DPPH) assay was performed to evaluate the antioxidant activity of these diterpenes.
This study demonstrates that ferruginol exhibits the strongest antioxidant activity among the
diterpenes isolated from T. cryptomerioides heartwood.
Hydrothermolysis of Flavonoids in Relation to Steaming of Japanese Larch Wood
Authors: Ohmura W. , Ohara S. , Hashida K. , Aoyama M. , Doi S.
Published: September 2004

Four flavonoid compounds, ((+)-taxifolin, (+)-aromadendrin, quercetin and (−)-naringenin), from
Japanese larch (Larix leptolepis) wood were heated at 170 ℃C for 60 min at pH=3.46 (hydrothermolysis
treatment). Alphitonin, four taxifolin steric isomers and quercetin were recovered from
the treatment of (+)-taxifolin, and maesopsin, four aromadendrin steric isomers and kaempferol
from (+)-aromadendrin. The reaction products from (−)-naringenin were found to be a mixture
with (+)-naringenin. Quercetin was not changed by the treatment. Possible pathways for the formation
of these products are discussed.
Impact of Pulping Conditions on FORMACELL Aspen Lignin: Investigation of Methoxyl and Ester Groups, Carbohydrates, Molar Mass and Glass Transition Temperatures
Authors: Lehnen R. , Saake B. , Nimz H. H.
Published: September 2004

The influence of reaction time, reaction temperature and acid concentration on the yield and characteristics of FORMACELL aspen lignins were investigated. 18 samples were quantitatively isolated from the black liquor by precipitation. The samples were analysed regarding their contents of carbohydrates, methoxyl and ester groups. All samples had low carbohydrate contents and the amount of methoxyl and ester groups was continuously reduced under more severe pulping conditions. Molar mass distributions and glass transition temperatures were determined. Molar masses of lignins were continuously reduced during pulping resulting in low weight average molar masses from 2.500–3.200 g/mol. Glass transition temperatures varied from 123.6 to 154.5°C, depending on the reaction conditions. Comparison of the thermograms with those of the lignins from the Kraft or Sulfite process confirmed that in the FORMACELL process a very uniform lignin with few impurities is obtained.
Ethanol-Enhanced Alkaline Pulping of Arundo donax L. Reed: Influence of Solvent on Pulp Yield and Quality
Authors: Shatalov A. A. , Pereira H.
Published: September 2004

The effect of solvent on yield and properties of ethanol-alkali pulps from Arundo donax L. was
studied. Selectivity of pulping was significantly improved with increase in solvent proportion in the
cooking liquor. A rise in ethanol concentration from 20 to 60% (by vol.) increased pulp yield from
44.0 to 48.9%, while decreasing residual lignin from 5.0 to 3.0%. Ethanol addition had a positive
effect on preservation of carbohydrate complex against degradation in alkaline medium. Intrinsic
viscosity of cellulose was improved up to 35% and xylan content increased from 8.6 to 12.1% with
increase in ethanol concentration from 20 to 60%. The preservation of minor non-cellulosic polysaccharides
with solvent addition was also observed. The papermaking properties of ethanol-alkali
pulps were best for 20% ethanol content. An increase in solvent charge led to a drop in burst,
tear and tensile pulp strength. Solvent addition assisted the conversion of glucuronic to hexenuronic
acids, whereas the content of HexA in ethanol-alkali pulps of Arundo donax (about
10 μmol/g) was substantially lower than reported for kraft pulps from wood.
Reflectance FTIR Microspectroscopy for Studying Effect of Xylan Removal on Unbleached and Bleached Birch Kraft Pulps
Authors: Ristolainen M. , Alén R. , Malkavaara P. , Pere J.
Published: September 2004

The effect of the partial removal of xylan on unbleached and bleached birch kraft pulps was investigated
by Fourier transform infrared (FTIR) microspectroscopy and the resulting data were analyzed
by multivariate data analysis, i.e., principal component analysis (PCA) and maximum likelihood
principal component analysis (MLPCA). Isolated model substances (xylan, cellulose and
lignin) were used to calibrate these methods. Clear chemical changes in the relative proportions of
the main constituents and functional groups on the pulp fiber surface were observed as a function
of the amount of xylan removed. In addition, due to the partial removal of xylan, indications of
some physical changes were observed.
Detection on Incipient Fungal Attack in Wood Using Magnetic Resonance Parameter Mapping Wood Studied by Liquid State NMR Measurements
Authors: Müller U. , Bammer R. , Teischinger: A.
Published: September 2004

Magnetic resonance imaging delivers excellent, high-resolution spatial images of damp or wet
wood that can supply information on internal defects of logs to optimise cutting patterns. In normal
wood, the image contrast of magnetic resonance images is primarily influenced by the distribution
of moisture content within the specimen. In the case of fungal attack, it is also affected by the inherent
Spin-Lattice (T1) and Spin-Spin (T2) relaxation times. We investigate changes in relaxation
times in beech wood (Fagus sylvatica L.) caused by fungal attack (Coniophora puteana (Schum.)
Karst.) over 6 weeks. In addition, loss of compressive strength and mass loss were tested, allowing
comparison to conventional methods. Magnetic resonance imaging showed superior sensitivity in
detection of early stage of fungal decay in comparison to mass or strength loss assessment.
Wood Density Determination by X- and Gamma-Ray Tomography
Authors: Macedo A. , Vaz C. M. P. , Pereira J. C. D. , Naime J. M. , Cruvinel P. E. , Crestana S.
Published: September 2004

Wood density measurement is related to several factors that influence wood quality. In this paper,
a CT image calibration procedure which allows image quantification in terms of dry bulk density is
presented for three different X- and gamma-ray energies (28.3, and 59.5, and 662.0 keV). The mass
attenuation coefficients measured for a set of eight wood species did not vary significantly, allowing
a single calibration for determination of bulk density of air-dried wood samples at each energy.
The equation for bulk density calibration obtained was validated using a second set of twelve
wood species. Comparison of bulk density determined by CT images, using the calibration procedure
proposed, with values obtained by gravimetric methods, presented a very good linear correlation
coefficient (R2=0.94). The main advantage of CT imaging over conventional techniques for
wood bulk density determination is that it allows detection and quantification of heterogeneities
and internal defects. At the sub-millimetric spatial resolution level, it is possible to identify morphological
and structural aspects of wood samples.
The Influence of Wood Specimen Surface Coating on Moisture Movement during Drying
Authors: Baronas R. , Ivanauskas F.
Published: September 2004

A model of wood drying under isothermal conditions taking into consideration coating of the surface
of a specimen is presented in this paper in a two-dimensional formulation. The influence of
the surface coating degree as well as geometrical shape of a wood specimen on the dynamics of
drying is investigated. Exponentials, describing the dependence of the halfdrying time on the degree
of coating of the edges, as well as on the ratio of the width to the thickness of the transverse
section of specimens from the northern red oak (Quercus rubra), are presented for drying from
above the fiber saturation point. This paper describes the conditions of usage of the two-dimensional
moisture transfer model in contrast to the one-dimensional model for accurate prediction of
the drying process taking into consideration the coating of edges of specimens having a rectangular
transverse section. A measure of reliability of the one-dimensional model to predict the wood
drying process of sawn boards is introduced in this paper.
Study of the System Wood – Coating Material. Part 2.Wood – Solid Coating Material
Authors: Liptáková E. , Kúdela J.
Published: September 2004

This paper deals with the intermolecular forces in the system wood-solid coating, which primarily
condition the stability of the system. Further, it points out a series of secondary factors that significantly
distort the results of interactions between surface forces; not only influencing the phase
boundary wood-coating material in the liquid phase, but also negatively impacting the wood-solid
coating system stability.
Flake Drying Temperature Affects Mat Properties during Pressing
Authors: Martino C. J. , Shrauti S. , Banerjee S. , Otwell L. P. , Price E. W.
Published: September 2004

The contact angle of water on wood rises sharply as the wood approaches dryness. The general shape
of the rise can be reproduced through thermodynamic calculations that consider the presence of extractives
on the surface. SEM work confirms that extractives move progressively to the surface with
increasing drying temperature. Other factors such as pore closure also contribute to surface hydrophobicity.
The temperature profile within a stack of flakes during accelerated pressing shows a
break at 100°C when flakes dried at high temperature are processed. Moisture is known to be driven
from the outer layers of the stack to the core during early pressing. If the flake surface is hydrophobic
then this moisture would film on the surface rather than penetrate into the flake. Subsequent evaporation
of the moisture would lead to high pressure. Hence, flakes dried at high temperature should be
more prone to delamination. High-temperature drying also promotes VOC emissions and there
should be operational and environmental benefits to drying at lower temperature.
Molecular Identity of Species and Isolates of the Coniphora Cellar Fungi
Authors: Schmidt O. , Grimm K. , Moreth U.
Published: September 2004

Within the genus Coniophora, C. puteana and the less common species C. marmorata, C. arida and
C. olivacea form a group of domestic brown-rot fungi (“cellar fungi”), which cause considerable
decay in the woodwork of buildings. The fungi are difficult to distinguish by their fruit bodies. Traditional
methods fail to identify species in a pure culture. Also with regard to decay of wood in use,
the basidiomes rarely develop, and the surface mycelium on wood is sparse except for the fine dark
strands. Thus, molecular techniques were applied to obtain a reliable method for differentiation
and detection and to aquire a greater knowledge of the domestic Coniophora species. Isolates obtained
from decayed wood and from culture collections and identified as domestic Coniophora
species were used. The internal transcribed spacer (ITS) of the ribosomal DNA was amplified by
polymerase chain reaction, sequenced and restricted by the endonuclease TaqI. The ITS sequences
characteristic of C. puteana, C. arida, C. marmorata and C. olivacea were obtained and entered into
the international databases. The sequence size ranges from 525 to 729 bp. The data supplement our
collection of ITS sequences from domestic wood decay fungi built for the characterization of
mycelium in culture. Most isolates belong to C. puteana and some to C. arida, C. marmorata and C.
olivacea. Two other isolates belong to a further Coniophora species close to C. olivacea. Obviously,
at least five Coniophora species occur within European buildings. Many of the isolates were not
correctly identified. Consequently, the traditional characterization methods used, viz., growth rate,
temperature influence and wood weight loss, were less suitable for the differentiation of Coniophora
species as formerly anticipated.
Modification of Spruce Lignans with Trametes hirsuta Laccase
Authors: Buchert J. , Mustranta A. , Tamminen T. , Spetz P. , Holmbom B.
Published: September 2004

The effect of Trametes hirsuta laccase on isolated spruce wood lignans was evaluated. Lignans
were isolated from the heartwood of spruce branches and treated with different laccase dosages
and treatment times. The effect of the treatment was monitored by gas chromatography, size exclusion
chromatography and ionization difference UV spectroscopy. Lignans were efficiently oxidized
by T. hirsuta laccase. About half of the phenolic groups present in lignans remained intact
during the treatment. The oxidation of phenolic groups in lignans produced oligomeric structures
containing approximately 4–5 lignan units (i.e., 8–10 phenyl propane units). Precipitation of the
formed oligomeric structures probably prevented further polymerization.
Alkaline Hydrolysis of Nonphenolic β-0-4 Lignin Models: Substituent Effect of the A-Ring on the Rate
Authors: Schultz T. P. , Fisher T. H.
Published: September 2004

Six nonphenolic β-0-4 lignin models substituted on the phenyl A-ring [unsubstituted; 3,5-dimethoxyl; 3,4-dimethoxyl; 3-methoxyl; 4-methoxyl; and 4-methyl] were synthesized and the alkaline
hydrolysis rates at 170°C determined. Electron-withdrawing substituents enhanced the hydrolysis
rate, but this effect was relatively minor. Over 90% of the disappearance of the dimer
could be accounted for by appearance of the B-ring phenolic product for all compounds, which
suggests that minimal side reactions occurred.
Photosensitized Delignification of Residual Lignin and Chemical Pulp from Eucalyptus grandis Wood
Authors: Perez D. Da Silva , Castellan A. , Nourmamode A. , Grelier S. , Ruggiero R. , Machado A. E. H.
Published: September 2004

Bleached pulps were obtained from a Eucalyptus grandis peroxyformic/formic acid chemical pulp
using oxygen, hydrogen peroxide, photosensitizers (methylene blue, Fe (II) 4,4′,4″,4‴-tetrasulfophthalocyanine,
hemin, hematoporphyrin) and/or TiO2. Residual lignin of unbleached pulp, isolated
and characterized by size exclusion chromatography, 31P NMR and thioacidolysis, was used to
study the photochemical reactions occurring during the bleaching process. The main reactions
were conversion of phenolic aromatic units into carboxylic acids and cleavage of the β-O-4 ether
bonds leading to a depolymerization of the lignin framework into smaller fragments.
New Method to Follow the Dimerisation Reaction Occuring during Oxidation of 4-Ethylguaiacol
Authors: Sippola V. , Viljava T.-R. , Vilonen K. , Krause O.
Published: September 2004

4-Ethylguaiacol is a phenolic model compound used to study the oxidation of lignin. A new method
was developed to determine 4,4′-diethyl-6,6′-biguaiacol, an unwanted side-product, in the oxidation
of 4-ethylguaiacol. The sample is extracted with ethyl acetate to separate 4,4′-diethyl-6,6′-biguaiacol
from the water-soluble oxidation catalyst. No other treatment is required before analysis with a standard
UV-Vis spectrophotometer. The spectrophotometer is calibrated to measure concentrations of
4,4′-diethyl-6,6′-biguaiacol up to 0.3 mM. With the new method, the concentrations of 4,4′-diethyl-6,6′-biguaiacol can be reliably determined over a wide alkaline pH range. The performance of the
method was demonstrated in experiments investigating the formation of 4,4′-diethyl-6,6′-biguaiacol
in the autoxidation and cobalt-sulphosalen catalysed oxidation of 4-ethylguaiacol. In the conditions
of the studies (1 bar oxygen pressure and 50°C), a low (0.01 mM) concentration of Co-sulphosalen
clearly increased the total conversion of 4-ethylguaiacol. However, relative to autoxidation, the conversions
achieved in the presence of the catalyst were just as sensitive to pH, and the yields of the undesired
dimeric product, 4,4′-diethyl-6,6′-biguaiacol, were higher.
Surface Chemistry of Eucalyptus Wood Pulp Fibres: Effects of Chemical Pulping
Authors: Fardim P. , Durán N.
Published: September 2004

The surface chemistry of Eucalyptus grandis wood pulp fibres was investigated using the sessile
drop apparent contact angle, XPS and TOF-SIMS techniques. Pulp fibres were studied using different
chemical pulping conditions. The pulping affected the surface coverage of lignin and extractives,
as indicated by XPS, and the work of adhesion with water, as estimated from contact angle
determinations. The amount of surface lignin decreased while surface extractives and work of adhesion
with water increased in relation to the amount of active alkali used in the pulping. Desorption
and analysis of surface extractives by TOF-SIMS showed sterols, fatty acid calcium and sodium
salts. After acetone extraction the spectra obtained by TOF-SIMS showed changes. However, calcium
and sodium salts of fatty acids were still detected, indicating their resistance to solvent extraction.
This resistance to extraction can affect the lignin and extractive surface coverage estimations
using XPS due to the contribution of the carbon content after extraction. The extent of
interference was, however, uncertain.
Delignification Mechanism during High-Boiling Solvent Pulping. Part 2. Homolysis of Guaiacylglycerol-β-Guaiacyl Ether
Authors: Kishimoto T. , Sano Y.
Published: September 2004

A phenolic β-O-4 type lignin model compound, guaiacylglycerol-β-guaiacyl ether, was treated with
70 wt % aq 1,4-butanediol solution at 180°C to investigate the delignification mechanism under
high-boiling solvent (HBS) pulping conditions. Thirteen compounds including four monomers, six
dimers, two trimers and a tetramer were isolated from the reaction products. Most of these products
were generated by recombination of phenoxy radicals formed by homolysis of the β-aryl
ether. The results suggest that phenolic β-O-4 linkages in lignin are cleaved homolytically (radical
mechanism) via quinone methide intermediates under HBS pulping conditions.
Influence of Coating Additives on Water Vapour Absorption and Desorption in Norway Spruce
Authors: Ekstedt J.
Published: September 2004

The growing concern for the environment and occupational health aspects have led to the development
and use of waterborne coatings for architectural applications. These coatings can be considered
as a two-phase system with the binder emulsified or dispersed in the water phase. During
film formation, phase separation occurs and coating additives can be mobilised and transported
into wood, thus changing wood moisture sorption characteristics. In the present study, wood samples
were treated with various coating additives, normally used in waterborne coatings, and exposed
to various humid conditions. The moisture adsorption and desorption in the treated wood
samples was compared to untreated wood samples. It is shown that the presence of substances
common in waterborne coatings changes the moisture sorption characteristics of wood. The presence
of a surfactant, nonylphenol ethoxyphenoxylate adduct, and the presence of a rheology modifier,
hydroxyethyl cellulose, lower the rate of moisture absorption and, to a great extent, delay the
release of moisture during desorption. Due to the fact that these substances occur in waterborne
coatings, may be mobilised during and after film formation and accumulate at the coating/substrate
interface, there is a great probability that these substances change the moisture sorption
characteristics of the wood substrate in an unfavourable way and create unexpected moisture conditions
at the coating/wood interface.
In situ Longitudinal Tensile Tests of Pine Wood in an Environmental Scanning Electron Microscope
Authors: Sippola M. , Frühmann K.
Published: September 2004

To study wood fracture on its cellular level, small tensile specimens of pine (Pinus sylvestris [L.])
were fractured in situ in tension inside the chamber of an ESEM (Environmental Scanning Electron
Microscope). Fractured surfaces of macroscopic tensile test specimens were also studied with
an ESEM. The same kind of fracture phenomena were observed in both small and large specimens.
The in situ tests proved to be reproducible and the results revealed typical fracture propagation0
directions and order in softwood under longitudinal tension. The gradual change of material
properties of wood in the radial direction was found to strongly influence the fracture process.
The influence of personality and anxiety on the oral performance of Japanese speakers of English
Authors: Oya Taeko , Manalo Emmanuel , Greenwood Jackie
Published: September 2004

This study investigated the relationship between personality and anxiety characteristics of Japanese students and their oral performance in English. The participants were 73 native‐speakers of Japanese who were studying English at various language schools in New Zealand. They were administered the Maudsley Personality Inventory, the Spielberger State Anxiety Inventory, and a story‐retelling task which was scored in terms of oral fluency, accuracy, complexity, and global impression. Significant correlations were found between extraversion and global impression scores, and state anxiety and clause accuracy scores. These findings suggest that participants who were more extraverted produced better global impressions during their oral performance, and those who were experiencing higher levels of state anxiety made more errors in their spoken use of clauses. Copyright © 2004 John Wiley & Sons, Ltd.
Inorganic Nanotubes
Authors: Remškar M.
Published: September 2004

Since the first report on the synthesis of inorganic WS2 nanotubes in 1992, the number of articles on the successful growth of different inorganic nanotubes has increased rapidly, emphasizing the importance of this field for nanotechnology. Although there are some geometrical similarities to carbon nanotubes, inorganic nanotubes are distinguished by important peculiarities, from their growth mechanisms to the physical and chemical properties that are attractive for potential applications. Their structural properties, which are important for such applications, are discussed in this review.
Essential thrombocythemia terminating in pure erythroleukemia
Authors: Kreft Andreas , Burg Jürgen , Fischer Thomas , Kirkpatrick Charles James
Published: September 2004

Transformation into acute leukemia is a rare event in essential thrombocythemia (ET). The blasts are usually of myeloid, rarely of megakaryoblastic differentiation. We present the case of a patient with pure erythroleukemia after a nearly 10‐year course of ET, which was treated with hydroxyurea. The patient, a 58‐year‐old male, presented with an elevated thrombocyte count (926,000/μL) and normal values of hemoglobin and leukocytes. After 10 years of therapy with hydroxyurea, the patient developed acute leukemia of solely erythroid differentiation. Chemotherapy with cytarabine and daunorubicin resulted in incomplete remission. The patient died 2 months after diagnosis of acute erythroleukemia. Transformation of ET into erythroleukemia may demonstrate the pluripotent potential of the neoplastic hemopoietic stem cell, with the ability to cause acute leukemia not only of myeloid or megakaryoblastic but also of erythroid lineage. Am. J. Hematol. 77:140–143, 2004. © 2004 Wiley‐Liss, Inc.
Rituximab for treatment of refractory/relapsing thrombotic thrombocytopenic purpura (TTP)
Authors: Ahmad Afaq , Aggarwal Anita , Sharma Daya , Dave Harish P. , Kinsella Virginia , Rick Margaret E. , Schechter Geraldine P.
Published: September 2004

Plasma exchange is the standard treatment for thrombotic thrombocytopenic purpura (TTP). For patients refractory to plasma exchange, treatment options are limited and often unsuccessful. The platelet thrombi that form in acquired TTP are believed to result from the presence of procoagulant ultralarge multimers of von Willebrand factor (VWF) in the circulation due to autoantibody inhibition of VWF cleaving protease (ADAMTS‐13), the enzyme that normally cleaves the ultralarge multimers. Rituximab, a chimeric monoclonal antibody against CD20, has been recognized as a useful therapy for antibody‐mediated autoimmune disease. We therefore treated four patients with recurrent TTP with 2 or 4 weekly doses of rituximab in addition to corticosteroids, vincristine, plasma, or continuing plasma exchange. Three patients responded with prompt improvement in microangiopathic hemolytic anemia and thrombocytopenia, which allowed plasma exchange to be discontinued or avoided and prednisone to be rapidly discontinued. Two of the 3 responders have remained in unmaintained complete remission for 13+ months. The third patient relapsed at 13 months; a second course of rituximab and prednisone resulted in an unmaintained remission for 6+ months. All four patients were tested for ADAMTS‐13 activity and its inhibitor at a point in their course when samples were available. Low ADAMTS‐13 activity was noted in 3 patients tested at relapse, and the inhibitor activity was detectable in 2 patients. ADAMTS‐13 activity increased during remission in one of these 2 patients although the patient had a persistence of the inhibitor. One patient tested only during remission had a normal ADAMTS‐13 level. We conclude that rituximab may have a role and deserves further study in the treatment of patients with relapsing TTP. Am. J. Hematol. 77:171–176, 2004. © 2004 Wiley‐Liss, Inc.
Genetic variants implicated in personality: A review of the more promising candidates
Authors: Savitz Jonathan B. , Ramesar Rajkumar S.
Published: September 2004

Alleles of the serotonin transporter gene (SERT) and the dopamine 4 receptor gene (DRD4) were first associated with anxiety‐related and novelty‐seeking personality traits, respectively, in 1996. These early successes precipitated a flood of research into the genetic basis of personality; a quest that has yet to yield decisive answers. Here, both the theoretical and the empirical evidence implicating specific loci—in particular SERT and DRD4—in the development of personality is evaluated. Despite a paucity of statistically significant results following post‐hoc analysis, and an excess of positive results derived from studies with small sample sizes, the existence of a genuine effect is argued for: a gene‐personality relationship rendered periodically latent through genetic epistasis, gene–environment interactions, variation in genetic background, and the presence of other confounding variables. © 2004 Wiley‐Liss, Inc.
Phenotype studies of the DRD4 gene polymorphisms in ADHD: Association with oppositional defiant disorder and positive family history
Authors: Kirley Aiveen , Lowe Naomi , Mullins Celine , McCarron Mary , Daly Grainne , Waldman Irwin , Fitzgerald Michael , Gill Michael , Hawi Ziarih
Published: September 2004

The objective of this study was to investigate association of DRD4 polymorphisms with ADHD subtypes for which there is evidence for increased heritability. The genetic variants tested were the 120 bp insertion/deletion, the −616, −521, −376, and the 48 bp DRD4 VNTR. The primary analyses were of association with oppositional defiant disorder (ODD), conduct disorder (CD), and diagnostic subtypes. Secondary analyses of clinical subtype were exploratory in nature and included analysis of association of DRD4 polymorphisms with family history of ADHD. We observed significant association between DRD4 7‐repeat allele transmission and ADHD children with comorbid ODD (χ2 = 6.74, df = 1, P = 0.01, OR = 2.45) The DRD4 7‐repeat allele was also significantly associated with family history positive ADHD (χ2 = 10.12, df = 1, P = 0.0021, OR = 3.57). We observed no significant distortion in the transmission of any of the tested DRD4 variants with inattentive or hyperactive‐impulsive subtypes or symptom dimensions. In conclusion, our findings of increased DRD4 7‐repeat allele transmission in ODD extend those reported by Holmes et al. [2002: Am J Med Genet Neuropsychiatr 114:150–153]. To our knowledge, this is the first study to report association of the DRD4 7‐repeat allele with ADHD children who have a positive family history of ADHD. Overall, the results from this study support the investigation of clinical subtypes in molecular genetic studies of ADHD. © 2004 Wiley‐Liss, Inc.
Ketogenic treatment reduces deleted mitochondrial DNAs in cultured human cells
Authors: Santra Sumana , Gilkerson Robert W. , Davidson Mercy , Schon Eric A.
Published: September 2004

Impairment of mitochondrial energy metabolism has been associated with a wide range of human disorders. Large‐scale partial deletions of mitochondrial DNA (mtDNA) cause sporadic Kearns–Sayre syndrome, a fatal multisystem disorder, in which the majority of mtDNAs in affected tissues have deletions (Δ‐mtDNAs). Since most mtDNA‐related diseases, including Kearns–Sayre syndrome, are recessive, only a few wild‐type mtDNAs can compensate for the deleterious effects of many Δ‐mtDNAs. We have developed a pharmacological approach to reduce the proportion of Δ‐mtDNAs in vitro, in which we grow cells in medium containing ketone bodies, replacing glucose as the carbon source. Cells containing 100% Δ‐mtDNA died after 5 days of treatment, whereas those containing 100% wild‐type mtDNA survived. Furthermore, in a cloned heteroplasmic cell line, the proportion of wild‐type mtDNA increased from 13% initially to approximately 22% after 5 days in ketogenic medium and was accompanied by a dramatic improvement in mitochondrial protein synthesis. We also present evidence that treatment with ketone bodies caused “heteroplasmic shifting” not only among cells (ie, intercellular selection) but also within cells (ie, intracellular selection). The demonstration that ketone bodies can distinguish between normal and respiratorily compromised cells points to the potential use of a ketogenic diet to treat patients with heteroplasmic mtDNA disorders. Ann Neurol 2004
Electromyography guides toward subgroups of mutations in muscle channelopathies
Authors: Fournier Emmanuel , Arzel Marianne , Sternberg Damien , Vicart Savine , Laforet Pascal , Eymard Bruno , Willer Jean‐Claude , Tabti Nacira , Fontaine Bertrand
Published: September 2004

Myotonic syndromes and periodic paralyses are rare disorders of skeletal muscle characterized mainly by muscle stiffness or episodic attacks of weakness. Familial forms are caused by mutations in genes coding for skeletal muscle voltage‐gated ion channels. Exercise is known to trigger, aggravate, or relieve the symptoms. Therefore, exercise can be used as a functional test in electromyography to improve the diagnosis of these muscle disorders. Abnormal changes in the compound muscle action potential can be disclosed using different exercise tests. We report the outcome of an inclusive electromyographic survey of a large population of patients with identified ion channel gene defects. Standardized protocols comprising short and long exercise tests were applied on 41 unaffected control subjects and on 51 case patients with chloride, sodium, or calcium channel mutations known to cause myotonia or periodic paralysis. These tests disclosed significant changes of compound muscle action potential, which generally matched the clinical symptoms. Combining the responses to the different tests defined five electromyographic patterns (I–V) that correlated with subgroups of mutations and may be used in clinical practice as guides for molecular diagnosis. We hypothesize that mutations are segregated into the different electromyographic patterns according to the underlying pathophysiological mechanisms. Ann Neurol 2004
Effect of operation conditions in the pervaporation of ethanol–water mixtures with poly(1‐trimethylsilyl‐1‐propyne) membranes
Authors: González‐Marcos Jose A. , López‐Dehesa Cristina , González‐Velasco Juan R.
Published: September 2004

Poly(1‐trimethylsilyl‐1‐propyne) (PTMSP) is known to show preferential permeation of ethanol in the pervaporation of ethanol–water mixture. Although this polymer presents good characteristics for the separation of organic–water solutions, operation conditions and membrane characteristics, such as thickness, affect its pervaporation performance. The effect of temperature and feed concentration on pervaporation was studied. During pervaporation of 10 wt % ethanol–water solution, the separation factor (αH2OEtOH) remains almost constant, whereas the permeation flux (F) increases exponentially with operation temperature. On the other hand, the separation factor decreases, whereas the permeation flux increases with ethanol content in the feed mixture. The membrane thickness also affects the performance of PTMSP polymer films: selectivity increases sharply with membrane thickness up to 50 μm, whereas it remains constant for thicker membranes. The permeation flux decreases with membrane thickness in the whole range studied. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94:1395–1403, 2004
Preparation of linear low‐density polyethylene by in situ copolymerization of ethylene with Zr supported on montmorillonite/Fe/methylaluminoxane catalyst system
Authors: Zhang Zhicheng , Guo Cunyue , Cui Nannan , Ke Yucai , Hu Youliang
Published: September 2004

Linear low‐density polyethylene (LLDPE) was prepared by in situ copolymerization of ethylene with dual‐functional catalysts that were composed of rac‐Et(Ind)2ZrCl2 supported on montmorillonite (MMT) and {[(2‐ArNC(Me))2C5H3N]FeCl2} [Ar = 2,4‐C6H4(Me)2] oligomerization catalyst. A series of polyethylenes with different degrees of branching were obtained by adjusting the ratio of Fe and Zr (Fe/Zr). DSC, NMR, GPC, SEM, and density‐gradient method were used to characterize the polymers. With increasing Fe/Zr ratio, the densities and melting points of polymers decreased, whereas the branching degrees and molecular weights increased. When the Fe/Zr ratio was increased, the activities of the catalysts decreased at atmospheric pressure and increased at 0.7 MPa ethylene pressure. SEM micrographs revealed that the morphology of branched polyethylene, produced with the catalyst supported on MMT, is better than that produced by the catalyst in a homogeneous system. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1690–1696, 2004
The effect of bimodality on the tear properties of filled silicone networks
Authors: Shah Gul Bali
Published: September 2004

The effect of blending a short and a long chain silicone prepolymer, that is, the effect of bimodality on tear properties of filled polymer networks has been investigated. Two concentrations, namely, 17.2 and 30.2% w/w of the filler (HDK) were used. The contents of short chain prepolymers have been varied from 0 to 69% w/w and 0 to 58% w/w for 17.2 and 30.2% filled polymer, respectively. The concentration of crosslinker and catalyst added were kept constant, namely, 13.79 and 0.07%, respectively, for each composition. It has been shown that up to a threshold concentration of filler and short chain prepolymers, the application of bimodality has beneficial effects of increasing tear energy up to 3.5 times that of the tear energy of the concerned filled monomodal polymer network. Above this threshold limit, further increase in concentration of filler or short chain prepolymers, contrary to expectation, adversely affected the tear properties of the filled polymer networks. In light of the results obtained, the mechanism of enhancement in the tear properties of the polymer network due to bimodality in the filled polymer system has been discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1719–1722, 2004