bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional connectivity in the pharmacologically activated brain: Resolving networks of correlated responses to d‐amphetamine
Authors: Schwarz Adam J. , Gozzi Alessandro , Reese Torsten , Bifone Angelo
Published: March 2007

We investigated the functional connectivity structure underlying the widespread relative cerebral blood volume (rCBV) response to d‐amphetamine in the rat brain by systematically analyzing the intersubject correlations between the response amplitudes in 48 atlas‐defined brain structures. A cluster analysis resolved three distinct networks of brain regions that exhibited closely coupled responses: one corresponding to primary dopamine projections from the midbrain to the striatum, a second consisting predominantly of forebrain cortical and basal ganglia regions that share a widespread correlation pattern resembling the univariate group response, and a third including structures in the periventricular dopamine system. These results suggest that different functional networks underlie the brain's response to d‐amphetamine. This approach may provide important new insights regarding the central systems that underlie pharmacological action. Magn Reson Med 57:704–713, 2007. © 2007 Wiley‐Liss, Inc.
Independent phase modulation for efficient dual‐band 3D imaging
Authors: Hargreaves Brian A. , Cunningham Charles H. , Pauly John M. , Daniel Bruce L.
Published: March 2007

Certain applications of MRI, such as bilateral breast imaging, require simultaneous imaging of multiple volumes. Although image data can be acquired sequentially, the SNR is often improved if both slabs are excited and imaged together, typically with phase encoding across a volume including both slabs and the space between them. The use of independent phase modulation of multiple slabs eliminates the need to encode empty space between slabs, which can result in a significant time reduction. Each slab is excited with a phase proportional to phase‐encode number such that the slab positions in the acquired data are shifted to reduce empty space. With careful consideration this technique is compatible with different pulse sequences (e.g., spin‐echo, gradient‐echo, RF spoiling, and balanced SSFP (bSSFP)) and acceleration strategies (e.g., partial k‐space and parallel imaging). This technique was demonstrated in phantoms and applied to bilateral breast imaging, where scan times were reduced by 20–30%. Magn Reson Med 57:798–802, 2007. © 2007 Wiley‐Liss, Inc.
Confirming the existence of five peaks in 129Xe rat head spectra
Authors: Kershaw Jeff , Nakamura Kazuhiro , Kondoh Yasushi , Wakai Atsushi , Suzuki Nobuko , Kanno Iwao
Published: March 2007

A series of experiments were performed to investigate why two peaks (D and E) of the five dissolved phase peaks in hyperpolarized 129Xe rat head spectra appeared inconsistently in previous work. Specifically, spectra were acquired under conditions of various shim states, anaesthetics, and arterial ligation. The shimming experiments showed that slice‐shimming can be used to improve resolution of the dissolved phase peaks, but even so, subtle changes in the shim state that may dramatically alter the shape of peak E remain poorly understood. Also, the inability to shim gas spaces and tissue simultaneously may explain why inconsistent chemical shift values have been reported in the literature. A possible solution for this problem is suggested. The results of pre‐ and postligation spectra from the same animal indicated that two peaks (A and E) originate from brain. Changing the anaesthetic was found to have no effect on the number of dissolved peaks in xenon spectra. Magn Reson Med 57:791–797, 2007. © 2007 Wiley‐Liss, Inc.
Toward accurate diagnosis of white matter pathology using diffusion tensor imaging
Authors: Budde Matthew D. , Kim Joong Hee , Liang Hsiao‐Fang , Schmidt Robert E. , Russell John H. , Cross Anne H. , Song Sheng‐Kwei
Published: March 2007

Diffusion tensor imaging (DTI) has been widely applied to investigate injuries in the central nervous system (CNS) white matter (WM). However, the underlying pathological correlates of diffusion changes have not been adequately determined. In this study the coregistration of histological sections to MR images and a pixel‐based receiver operating characteristic (ROC) analysis were used to compare the axial (λ∥) and radial (λ⟂) diffusivities derived from DTI and histological markers of axon (phosphorylated neurofilament, SMI‐31) and myelin (Luxol fast blue (LFB)) integrity, respectively, in two different patterns of injury to mouse spinal cord (SC) WM. In contusion SC injury (SCI), a decrease in λ∥ matched the pattern of axonal damage with high accuracy, but λ⟂ did not match the pattern of demyelination detected by LFB. In a mouse model of multiple sclerosis (MS), λ⟂ and λ∥ did not match the patterns of demyelination or axonal damage, respectively. However, a region of interest (ROI) analysis suggested that λ⟂‐detected demyelination paralleled that observed with LFB, and λ∥ decreased in both regions of axonal damage and normal‐appearing WM (NAWM) as visualized by SMI‐31. The results suggest that directional diffusivities may reveal abnormalities that are not obvious with SMI‐31 and LFB staining, depending on the type of injury. Magn Reson Med 57:688–695, 2007. © 2007 Wiley‐Liss, Inc.
Polyimide–silica hybrid coatings: morphological, mechanical, and thermal investigations
Authors: Karataş S. , Kayaman‐Apohan N. , Demirer H. , Güngör A.
Published: March 2007

In this study, polyimide–silica (PI–silica) based hybrid coating compositions were prepared from tetraethoxysilane (TEOS), γ‐glycidyloxypropyl trimethoxy silane (GOTMS), and polyamic acid (PAA) via a combination of sol–gel and thermal imidization techniques. PAA was synthesized from 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) and 3,3'‐Diaminodiphenyl sulfone (DDS) in N‐Methyl‐2‐pyrrolidone (NMP). The silica content in the hybrid coatings was varied from 0 to 20 wt%. The structural characterization of the hybrid coatings was performed using FTIR and 29Si‐NMR spectroscopies. Results from both pendulum hardness and micro indentation test show that the hardness of hybrid coatings improves with the increase in silica content. The tensile tests also demonstrated that the mechanical properties at low silica content are rather striking. Their surface morphologies were characterized by scanning electron microscopy (SEM). SEM studies revealed that inorganic particles were distributed homogenously through the PI matrix. It was also found that, incorporation of the silica domains increased the thermal stability of the hybrid coatings. Copyright © 2007 John Wiley & Sons, Ltd.
Prenatal diagnosis of oculocutaneous albinism type II and novel mutations in two Chinese families
Authors: Hongyi Li , Haiyun Wei , Hui Zheng , Qing Wenren , Honglei Duan , Shu Meng , Weiying Jiang
Published: March 2007

Objective

The prenatal genetic diagnosis and counseling of oculocutaneous albinism type II (OCA2) by detecting mutations in the OCA2 gene

Methods

DNA samples were extracted from peripheral whole blood and amniocentesis‐derived cells. Polymerase chain reaction and automatic sequence analysis were used to screen the OCA2 gene.

Results

Case 1: Two novel heterozygous mutations (p.N476D and p.Y827H) in the P gene were detected in the proband. Molecular prenatal diagnosis on fetal DNA revealed N476D. The pregnancy progressed uneventfully to a normal outcome. Case 2: Mutation analysis of the DNA of family 2 revealed compound heterozygosities for two novel P gene mutations (p.N476D and p.G775R). The pregnant female and the fetus each presented with a single P gene mutation (p.V443I and G775R, respectively). The pregnancy was continued.

Conclusion

This is the first report of prenatal diagnosis performed in families with oculocutaneous albinism type II (OCA2). Also, this report reveals three novel mutations of the P gene. Copyright © 2007 John Wiley & Sons, Ltd.
Syndromic encephalocele in a fetal case with a 1p35‐pter deletion and a 14q32‐qter duplication inherited from a maternal balanced translocation
Authors: Thauvin‐Robinet C. , Callier P. , Laurent N. , Rousseau T. , Masurel‐Paulet A. , Marle N. , Huet F. , Sagot P. , Faivre L. , Mugneret F.
Published: March 2007

Occipital encephalocele belongs to the family of neural tube defects, which occur in one among 2000 to 5000 live births. Syndromic encephaloceles include Meckel–Gruber syndrome and various chromosomal abnormalities. We report on a fetal case (13 WG) with bilateral cleft lip and palate, choanal atresia, occipital encephalocele, bilateral club feet, bilateral multicystic kidneys, enlarged bladder and urethral atresia. The fetal chromosome analysis showed a maternally inherited unbalanced translocation between the short arm of chromosome 1 and the long arm of chromosome 14, resulting in 1p35‐pter deletion and 14q32‐qter duplication (46,XY,der(1),t(1;14)(p35;q32)). Since the chromosomal breakpoints have not previously been implicated in syndromic encephalocele, this observation is of interest for the identification of other genes responsible for occipital encephalocele. Copyright © 2007 John Wiley & Sons, Ltd.
Prenatal diagnosis of Harlequin ichthyosis presenting as distal arthrogryposis using three‐dimensional ultrasound
Authors: Holden Simon , Ahuja Sapna , Ogilvy‐Stuart Amanda , Firth Helen V. , Lees Christoph
Published: March 2007

We describe a case of Harlequin Icthyosis where the main 2D and 3D ultrasound findings were digital contractures as opposed to the more commonly described severe facial dysmorphisms. A prenatal finding of distal arthrogryposis can therefore include harlequin icthyosis as a differential diagnosis, where 3D ultrasound may then disclose the facial features more commonly associated with the condition. Copyright © 2007 John Wiley & Sons, Ltd.
Evolution of hydrogen chloride from the surface of PVC wire‐insulation
Authors: Rickard E. F. , Conen B. H.
Published: March 2007

Long‐term dark ageing in the temperature range 35 to 91°C, has shown that hydrogen chloride is released in small but measurable quantities from the surface of fully‐stabilized PVC wire‐insulating compounds. The rate of release is temperature‐ and time‐dependent. For the particular formulations studied, there is an inverse dependence on the half‐power of neutralizer content. Risks to electrical circuit components associated with PVC insulation in enclosed equipment are assessed and shown to be negligible for most normal operating conditions.
Goniophotometric studies of film deterioration processes: I. Introduction and instrumentation
Authors: Quinney P. S. , Tighe B. J.
Published: March 2007

The use of reflectance techniques for the study of surface coatings is discussed and the applications of goniophotometry briefly reviewed. The necessary modifications to enable the Brice‐Phoenix light scattering photometer to be used as a high sensitivity goniophotometer are described together with details of the application of the instrument to the study of point films. Results obtained with different types of coatings are presented in order to show typical effects of variation in, for example: pigmentation, application technique and environmental deterioration. The results are discussed in terms of the subjectively assessed “gloss” of the different coatings and the ways in which the features of the goniophotometric curves may be most effectively and compactly described.

Goniophotometry is suggested as a potentially valuable and sensitive technique for the quantitative study of the early stages of deterioration of polymer films.
Thermodynamic parameters of polystyrene solutions in cyclohexane, determined from sedimentation—diffusion equilibria in the ultracentrifuge. dependence on concentration, temperature and molecular weight
Authors: Rietveld B. J. , Scholte Th. G. , Pijpers J. P. L.
Published: March 2007

Determination of the sedimentation–diffusion equilibrium is one of the methods furnishing data on the thermodynamic parameters of polymer solutions. By means of this procedure measurements can be performed over a considerable range of concentrations.

The equilibria in the ultracentrifuge have been determined for five polystyrene samples of narrow distribution covering the molecular weight range 2 × 104 to 2 × 106, at concentrations up to 40 wt‐% and at temperatures of 30, 45 and 65 °C.

The results are expressed in the data for the chemical potential of the solvent, the number‐average chemical potential of the polymer and the interaction parameter ξ. The results are compared with those obtained from osmotic pressure, light scattering and critical miscibility measurements. At very low concentrations the molecular weight dependence of the interaction parameter is in agreement with literature values derived from osmotic pressure and light scattering figures. At higher concentrations this molecular‐weight dependence decreases sharply but remains noticeable up to 40% concentration.
Mechanical properties of fibres of linear polyester‐and polyetherurethanes in relation to details of their chemical structures
Authors: Bleijenberg A. C. A. M. , Heikens D. , Meijers A. , Lampe H. G. M. , von Reth P. H.
Published: March 2007

Elastic fibres soluble in dimethylformamide were made from essentially linear polyester‐ and polyetherurethanes. The molecular structures of the polyurethanes were varied by using as chain extenders aliphatic diamines with a successively increasing number of carbon atoms. Mechanical investigations resulted in modulus, stress relaxation and creep data which oscillated with increasing number of carbon atoms of the diamines used. These results and the temperature‐ and time‐dependence of these data can be explained by a model proposing the existence of hard segment domains in a matrix of soft but crystallisable polyester or polyether material.
Degradation of high polymers in pipes with particular reference to the manufacture of synthetic fibres
Authors: Terrier François
Published: March 2007

A model is developed for the degradation of fibre‐forming high polymers. Overall degradation is divided into three types of degradation: (i) thermal degradation based on the mean residence time; (ii) thermal degradation in the boundary layers caused by a prolonged residence time at the walls; (iii) degradation induced by mechanical effects (this type of degradation occurs, in particular, at low temperatures, i.e. at high dynamic viscosities, since it is proportional to the shear stress). In an example, the degradation in a pipe is reduced to a minimum. It is stated that an optimum value can always be fixed for the tube diameter and the operating temperature.
A temperature‐sensitive band in the spectrum of polyvinyl acetate
Authors: Haken J. K. , Werner R. L.
Published: March 2007

The similarity of frequency and behaviour of a band showing increased intensity on heating in the spectrum of polyvinyl acetate observed at 1126 cm−1 to one previously observed in polyvinyl alcohol at 1142 to 1146 cm−1 is described. Several vinyl polymers of similar structure and the behaviour of the band in a copolymer structure have also been examined.
The use of high molecular weight polyacrylamides in the selective flocculation separation of a mineral mixture
Authors: Read A. D.
Published: March 2007

Most of the conventional mineral processing separation methods are not effective on mineral mixtures that contain a large percentage of slimes. Selective flocculation is a potentially attractive process for treating such mixtures. The process relies on achieving conditions under which the polymer flocculant adsorbs onto the surface of one mineral and not on the others. In a practical system this selective adsorption would have to be achieved under conditions of fluctuating water quality and mineral composition.

Partially hydrolysed polyacrylamides with a molecular weight of around 3 × 106 have been used in the selective flocculation separation of a synthetic finely‐divided mixture of haematite and a silicate (100% < 20 μm). It was possible to flocculate selectively from the mixture either the haematite or the silicate by using polyacrylamides of differing anionic character. It was usually necessary to employ a 1:1 electrolyte and a dispersant, in addition to the flocculant, to achieve good selectivity in this system.
Separation of polymer and copolymer mixtures by means of a disc centrifuge
Authors: Manley T. R. , Murray B.
Published: March 2007

By means of a disc centrifuge it is possible quickly and easily to separate the components of particulate mixtures of polymers and copolymers having different densities. The technique has been applied to mixtures and copolymers of PVC and PMMA, and PE and PVAc, but is believed to be of general application.
Investigations into the behaviour of “plumbonacrite” basic lead carbonate as a thermal stabiliser for polyvinyl chloride
Authors: Michell E. W. J.
Published: March 2007

An apparatus is described which permits reasonably uniform heat treatment of fairly large samples of PVC blends in controlled atmospheres, at preset temperatures, and for predetermined lengths of time. Experiments are described in which portions of a plasticised PVC blend, and also portions of an unplasticised PVC blend, were heated under nitrogen at 180 °C for various lengths of time up to those stages when Congo Red tests showed hydrogen chloride to be liberated. Each blend contained the basic lead carbonate “plumbonacrite”, 6PbCO3. 3Pb(OH)2.PbO, as stabiliser, and stearic acid as milling lubricant. Carbon dioxide evolved during the stabilising reactions was measured, and the crystalline solids in each heated PVC blend sample were studied by X‐ray diffraction.

The results obtained show that the plumbonacrite stabiliser in each PVC blend was used continuously and completely during the effective stabilisation period. The rates of carbon dioxide evolution were found to differ markedly between the plasticised and unplasticised blends, but in each case they could be described in terms of first order reaction kinetics. Correlation of these carbon dioxide measurements with the X‐ray diffraction results led to the conclusion that the stabilising reactions in the plasticised PVC blend took place mainly in solution, whereas these reactions in the unplasticised PVC blend seemed to take place within the plumbonacrite crystals themselves.

It is shown that these findings are consistent with previous work in these laboratories which has led to the idea that soluble lead compounds are formed by reaction of the basic lead stabiliser crystals with stearic acid milling lubricant, and that these compounds are in some way responsible for stabilising polyvinyl chloride against thermal decomposition. Further, it is suggested that the present results show that basic lead compounds act as thermal stabilisers for PVC in the true sense of the word. Considering in particular a radical chain mechanism for the thermal dehydrochlorination of polyvinyl chloride, a theory is proposed which explains how basic lead compounds can stabilise this polymer.
Structural characterisation of some polystyrene—polyisoprene copolymers
Authors: Price C. , Lally T. P. , Watson A. G. , Woods D. , Chow M. T.
Published: March 2007

The various levels of organisation which may be distinguished in non‐crystalline block copolymers are considered. An account is given of the application of low‐angle X‐ray diffraction and electron microscopy to the characterisation of the two‐phase morphology and grain texture of some styrene/isoprene copolymers. The first group of copolymers to be considered contains two series of samples of the type S–I, (S–I–)2X, (S–I–)3Y, and (S–I–)4Z where I is polyisoprene, S polystyrene and X, Y and Z are di‐, tri‐ and tetra‐functional coupling groups. The second group of copolymers which was subjected to a less detailed study than the first consists of just two polystyrene‐g‐polyisoprene samples.
The polymerisation of styrene on 13X zeolite
Authors: Barson C. A. , Knight J. R. , Robb J. C.
Published: March 2007

The polymerisation of styrene on 13X zeolite at 30°C has been studied. Rates of monomer consumption were determined dilatometrically, and the molecular weight distributions of the product were investigated by gel permeation chromatography. The effects of varying the weight of zeolite and the concentration of styrene were studied; the effects of preheating the zeolite samples to two different temperatures were also investigated. A cationic mechanism for the polymerisation is proposed; the initiation is on the zeolite surface and involves adsorbed water. The available space in the vicinity of the sites activated by water appears to determine the rate of propagation, and the molecular weight of the polymer.
Fifty years of polymer research
Authors: Huggins Maurice L.
Published: March 2007

The writer summarises his researches in the field of polymer science. He began with studies of the structures of space‐network and sheet polymers in crystals. Currently he is working on the structures of macro‐ions in silicate and borate crystals and glasses and on the development of a new theory of structures and thermodynamic properties of (polymer and other) solutions.
Dielectric properties of polar rubber mixtures
Authors: Hanna Faika F. , Abou‐Bakr Abdel‐Fattah
Published: March 2007

A systematic study of the dielectric properties of Perbunan N mixed with silica in increasing quantities is carried out in the frequency range 500 Hz to 1010 Hz at room temperature. The data are analysed using the Cole‐Cole method and the results are interpreted.
Exchange reactions as a basis of thermopiastic behaviour in crosslinked polymers
Authors: Campbell D. S.
Published: March 2007

An attempt has been made to achieve thermoplastic behaviour in a chemically crosslinked elastomer by arranging that the crosslinks should undergo rapid exchange at high temperatures. Natural rubber was chemically modified to give pendent hydroxyl groups which were then used as crosslinking sites to form β‐keto‐ester or malonate crosslinks. The resultant vulcanisates showed high stress relaxation rates in the temperature range 120 to 160°C and some degree of remouldability at 180°C. The incursion of permanent crosslinking prevented quantitative correlation between stress relaxation rates and chemical exchange rates of the crosslinking systems.
Runner flow in injection moulds
Authors: Sleeman Michael J. , West George H.
Published: March 2007

Runner flow in injection moulding has been investigated employing pressure drop, coloured tracer and birefringence measurements. Runners having a variety of lengths and numbers of elbows were employed and it was found that the results obtained could be explained in terms of a general non‐Newtonian fluid model with local heat generation. The characteristics of this type of flow are significantly different from isothermal laminar shear flow and suggest that practical advantages can result from the use of long runners containing a number of elbows in certain cases.
Formation of films from latices a theoretical treatment
Authors: Mason Geoffrey
Published: March 2007

Two published theoretical models for film formation from latices contain errors. These are corrected and new values of the criteria for film formation derived. In Brown's model the error is quite small (less than an order of magnitude) but for Vanderhoff's model the error completely invalidates the analysis. A new model is proposed in which the criterion for film formation is that the latex particles are liquid—a condition fulfilled above the polymer's glass transition temperature.
Gel permeation chromatography: Fast flow rate studies with porous glass column packings
Authors: Cooper Anthony R.
Published: March 2007

Comparisons have been made between gel permeation chromatograms obtained at solvent flow rates of 1.0 and 4.5 ml/min. Using a 24 ft column series packed with Bio Glas the pressure drop was 200 lb/in2 which is within the operating range of all gel permeation chromatographs and is considerably less than when crosslinked polystyrene gels are used. The chromatograms from the Bio Glas packed columns exhibited skewing, similar to that reported previously for polystyrene gel packed columns. An analysis of these chromatograms indicated that the increased peak width caused by the faster flow rate was serious. Typically Mw/Mn values calculated at 4.5 ml/min were double their true values. Additionally skewing badly distorted the differential molecular weight distribution for molecular weights of 411 000 and higher. Previous studies in this area had not described quantitatively this adverse effect of increasing solvent flow rate in gel permeation chromatography.
The 20S proteasome of Schistosoma mansoni: A proteomic analysis
Authors: Castro‐Borges William , Cartwright Jared , Ashton Peter D. , Braschi Simon , Guerra Sa Renata , Rodrigues Vanderlei , Wilson R. Alan , Curwen Rachel S.
Published: March 2007

Proteasomes are molecular machines found in virtually all cells that provide one of the mechanisms for protein turnover. We have analysed the 20S proteasome of Schistosoma mansoni, the first multimeric complex isolated from this helminth parasite. Three chromatographic steps were employed to yield a highly homogeneous preparation. 2‐DE of the purified complex revealed 58 spots, of which 46 could be assigned either an α or a β proteasome signature by MS. Most of the 14 transcripts (7α and 7β) encoded by the parasite genome were represented by multiple spots and we suggest that this diversity is due to PTMs of subunits. For most of the isoforms, variations in pI predominated although alterations in mass were also observed. 2‐DE separations of extracts from infective cercariae and blood‐dwelling adult worms probed by Western blotting, using a human anti‐α subunit antibody, revealed different patterns of reactivity, most probably in α3 and α6 subunits, on the basis of sequence conservation. This difference was rapidly lost following transformation of the cercaria to the skin schistosomulum stage, suggesting that changes in the proteasome structure, likely caused by the introduction of a new set of PTMs, precede remodelling of the parasite body prior to intravascular migration.
Biomarker clustering to address correlations in proteomic data
Authors: Carlson Scott M. , Najmi Amir , Cohen Harvey J.
Published: March 2007

Correlated variables have been shown to confound statistical analyses in microarray experiments. The same effect applies to an even greater degree in proteomics, especially with the use of MS for parallel measurements. Biological effects such as PTM, fragmentation, and multimer formation can produce strongly correlated variables. The problem is compounded in some types of MS by technical effects such as incomplete chromatographic separation, binding to multiple surfaces, or multiple ionizations. Existing methods for dimension reduction, notably principal components analysis and related techniques, are not always satisfactory because they produce data that often lack clear biological interpretation. We propose a preprocessing algorithm that clusters highly correlated features, using the Bayes information criterion to select an optimal number of clusters. Statistical analysis of clusters, instead of individual features, benefits from lower noise, and reduces the difficulties associated with strongly correlated data. This preprocessing increases the statistical power of analyses using false discovery rate on simulated data. Strong correlations are often present in real data, and we find that clustering improves biomarker discovery in clinical SELDI‐TOF‐MS datasets of plasma from patients with Kawasaki disease, and bone‐marrow cell extracts from patients with acute myeloid or acute lymphoblastic leukemia.
Structure and reactivity in the hydrolyses of aliphatic carboxylic acid esters and chlorides
Authors: C. Regan Andrew , Watt C. Ian F.
Published: March 2007

For hexanoic acid and its seven isomers, relative rates have been determined for acid catalysed esterification with methanol, and compared with those for saponification of the methyl esters. A good correlation between logarithms of relative rates for the two reactions is obtained, and it is suggested that the eight isomers provide a test set of compounds in which steric effects alone act on reactivity at the acyl carbon. A full set of steric parameters ($E_{\rm s}^\prime$ values) are presented. Rates of solvolyses of the acid chlorides of the isomers have been determined conductometrically in 3:1 wt:wt acetonitrile water. Logarithms of relative rates show a poor correlation with $E_{\rm s}^\prime$, and, taking into account the solvent dependence of the rates, the pattern excludes both rate‐limiting formation of a tetrahedral intermediate and rate‐limiting dissociation of chloride to form acylium ions. The remaining possibilities, a concerted process (AND) and rapid reversible formation of a hydrate followed by rate‐limiting dissociation of chloride (AN + D) are considered. Copyright © 2007 John Wiley & Sons, Ltd.
Direct NMR measurement of rotation rates: solvent effects on rotation barriers
Authors: Lomas John S.
Published: March 2007

2,2,4,4‐Tetramethyl‐3‐{2‐[3,4‐dialkoxy‐5‐(3‐pyridyl)]thienyl}pentan‐3‐ols self‐associate both in the solid state and in solution. The IR spectra of the solids display a broad OH absorption at 3320 cm−1, corresponding to an intermolecularly hydrogen‐bonded syn rotamer, probably a dimer, as well as absorptions around 3500 cm−1 of the intramolecularly hydrogen‐bonded anti form. Well‐crystallized samples of these derivatives go into solution in the syn form but undergo rotation to the anti rotamer at a rate which can be measured directly by proton Nuclear Magnetic Resonance (NMR) spectroscopy. The diethoxy derivative was studied in a wide variety of solvents. The activation energy for syn→anti rotation is practically solvent‐independent, whereas that of the reverse reaction falls in hydrogen‐bonding solvents, by more than 2 kcal mol−1 on going from chloroform or benzene to dimethylsulfoxide (DMSO). By combining direct measurements at low temperature and Dynamic Nuclear Magnetic Resonance (DNMR) results at high temperature, rotation rates were evaluated over a range of more than 100 K, and significantly large negative activation entropies determined. Copyright © 2007 John Wiley & Sons, Ltd.
Nanoindentation of biodegradable cellulose diacetate‐graft‐poly(L‐lactide) copolymers: Effect of molecular composition and thermal aging on mechanical properties
Authors: Lee Seung‐Hwan , Teramoto Yoshikuni , Wang Siqun , Pharr George M. , Rials Timothy G.
Published: March 2007

Nanoindentation of cellulose diacetate‐graft‐poly(lactide)s (CDA‐g‐PLLAs) synthesized by ring opening graft copolymerization of L‐lactide in bulk onto the residual hydroxyl positions on CDA were conducted to investigate the effect of the molecular composition and thermal aging on mechanical properties and creep behavior. Continuous stiffness measurement (CSM) technique was used to obtained hardness and elastic modulus. These material properties were expressed as a mean value from 100 to 300 nm depths and an unloading value at final indentation depth. The hardness and elastic modulus in all CDA‐g‐PLLAs were higher than those in pure CDA, indicating that the introduction of PLLA increases the hardness and elastic modulus. With an increase of crystallinity by thermal aging, the hardness and elastic modulus were increased in both CDA‐g‐PLLA and PLLA. The creep test performed by CSM showed that the creep strain of CDA was decreased by the grafting of PLLA. Thermal aging decreased the creep strain of CDA‐g‐PLLA and PLLA. With an increase of holding time, hardness was decreased, whereas elastic modulus was kept almost constant. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1114–1121, 2007
Local lamellar structures in banded spherulites analyzed by three‐dimensional electron tomography
Authors: Ikehara Takayuki , Jinnai Hiroshi , Kaneko Takeshi , Nishioka Hideo , Nishi Toshio
Published: March 2007

The lamellar morphology in banded spherulites of poly(ε‐caprolactone) blended with an amorphous polymer, poly(vinyl butyral), was investigated by three‐dimensional transmission electron tomography. It showed a local lamellar twist on a smaller scale than the band spacing by 2 orders of magnitude. It also indicated wavy lamellae and frequent variation in the direction of the lamellar plane. All these results indicated an S‐profiled lamellar structure; that is, the cross section perpendicular to the lamellar growth direction was S‐shaped. S‐profiled lamellae show these structures when they are sliced at a certain angle to the lamellar surface direction. Lamellar branching was also observed, but no screw dislocations that led to the formation of extinction rings were observed in this work. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1122–1125, 2007
Nonisothermal cold crystallization behavior and kinetics of polylactide/clay nanocomposites
Authors: Wu Defeng , Wu Liang , Wu Lanfeng , Xu Bin , Zhang Yisheng , Zhang Ming
Published: March 2007

The nonisothermal cold crystallization behavior of intercalated polylactide (PLA)/clay nanocomposites (PLACNs) was studied using differential scanning calorimetry, polarized optical microscope, X‐ray diffractometer, dynamic mechanical thermal analysis, and Fourier transform infrared spectrometer. The results show that both the cold crystallization temperature (Tcc) and melting point (Tm) of PLA matrix decreases monotonously with increasing of clay loadings, accompanied by the decreasing degree of crystallinity (Xc%) at the low heating rates (≤5 °C/min). However, the Xc% of PLACNs presents a remarkable increase at the high heating rate of 10 °C/min in contrast to that of neat PLA. The crystallization kinetics was then analyzed by the Avrami, Jezioney, Ozawa, Mo, Kissinger and Lauritzen–Hoffman kinetic models. It can be concluded that at the low heating rate, the cold crystallization of both the neat PLA and nanocomposites proceeds by regime III kinetics. The nucleation effect of clay promote the crystallization to some extent, while the impeding effect of clay results in the decrease of crystallization rate with increasing of clay loadings. At the high heating rate of 10 °C/min, crystallization proceeds mainly by regime II kinetics. Thus, the formation of much more incomplete crystals in the PLACNs with high clay loadings due to the dominant multiple nucleations mechanism in regime II, may have primary contribution to the lower crystallization kinetics, also as a result to the higher degree of crystallinity and lower melting point in contrast to that of neat PLA. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1100–1113, 2007
Study of Quantitative Structure–Retention Relationship (QSRR) of Gas Chromatography for Polychlorinated Dibenzothiophenes on Non‐polar Columns
Authors: Chen Shu‐Da , Liu Hong‐Xia , Wang Zun‐Yao
Published: March 2007

Optimized calculation of 135 Polychlorinated Dibenzothiophenes (PCDTs) was carried out at B3LYP/6‐31G* level with Gaussian 98 program. The structural and thermodynamic parameters identified with the Theoretical Linear Solvation Energy Relationship (TLSER) model were employed as theoretical descriptors in the Quantitative Structure–Retention Relationship (QSRR) models derived to predict Retention Indices (RI) of PCDTs. Two QSRR models developed for RI of PCDTs contain only one variable: the mean molecular polarizability (α) and entropy (S⊖), respectively. The best fitted equation for the correlation between RI and α of 25 PCDTs with experimental data was RI=−126.52(±2.86)+0.97(±0.01)α with R2 as 0.9942, SD as 2.22, suggesting high accuracy of the RI predicting model. The correlation between RI and S⊖ is strong, and the equation was RI=−184.17 (±3.09)+0.48(±0.01)S⊖ with R2 as 0.9961, SD as 1.81. Furthermore, using position of Cl substitution (NPCS) method, QSRR model of PCDTs was obtained: RI=6.23(±0.75)+13.36(±0.19)N with R2 as 0.9953, SD as 1.99. Method validation also showed that the three models of this study exhibit optimum stability. Finally, RI values of 110 PCDT congeners without experimental value were also predicted with the three models, respectively.
Influence of 15N enrichment on the net isotopic fractionation factor during the reduction of nitrate to nitrous oxide in soil
Authors: Mathieu Olivier , Lévêque Jean , Hénault Catherine , Ambus Per , Milloux Marie‐Jeanne , Andreux Francis
Published: March 2007

Nitrous oxide, a greenhouse gas, is mainly emitted from soils during the denitrification process. Nitrogen stable‐isotope investigations can help to characterise the N2O source and N2O production mechanisms. The stable‐isotope approach is increasingly used with 15N natural abundance or relatively low 15N enrichment levels and requires a good knowledge of the isotopic fractionation effect inherent to this biological mechanism. This paper reports the measurement of the net and instantaneous isotopic fractionation factor (α) during the denitrification of NO to N2O over a range of 15N substrate enrichments (0.37 to 1.00 atom% 15N). At natural abundance level, the isotopic fractionation effect reported falls well within the range of data previously observed. For 15N‐enriched substrate, the value of α was not constant and decreased from 1.024 to 1.013, as a direct function of the isotopic enrichment of the labelled nitrate added. However, for enrichment greater than 0.6 atom% 15N, the value of α seems to be independent of substrate isotopic enrichment. These results suggest that for isotopic experiments applied to N2O emissions, the use of low 15N‐enriched tracers around 1.00 atom% 15N is valid. At this enrichment level, the isotopic effect appears negligible in comparison with the enrichment of the substrate. Copyright © 2007 John Wiley & Sons, Ltd.
Laser‐induced photofragmentation of neutral and acidic glycans inside an ion‐trap mass spectrometer
Authors: Devakumar Arugadoss , Mechref Yehia , Kang Pilsoo , Novotny Milos V. , Reilly James P.
Published: March 2007

Permethylated acidic and neutral N‐glycans representing different types of glycan structures, such as linear and branched sialylated structures, high‐mannose type and fucosylated complex type, were photodissociated with 157 nm vacuum ultraviolet light in a linear ion trap. Cross‐ring fragments corresponding to high‐energy fragmentation pathways were observed in abundance for all studied structures. Some product ions appear diagnostic for a linkage of sialic acid residues and the glycan antenna to which these residues are attached. A conclusive assignment of the fucosylation site of the studied glycan structure has been facilitated through measurement of cross‐ring fragmentation resulting from photodissociation. Copyright © 2007 John Wiley & Sons, Ltd.
Stahl im Hochbau – ein nachhaltiger Werkstoff?
Authors: Maydl Peter , Passer Alexander , Cresnik Guido
Published: March 2007

Seit dem Brundtland Report [12] im Jahr 1985 “Unsere gemeinsame Zukunft” und dem Erdgipfel von Rio 1992 ist der Begriff “Nachhaltige Entwicklung” in unserer Gesellschaft allgegenwärtig. Nachhaltigkeit bedeutet demnach, die Bedürfnisse der heutigen Generationen zu decken, ohne die Möglichkeiten künftiger Generationen zu gefährden. Unter dem Begriff “Nachhaltiges Bauen” (engl. sustainable construction) versteht man, Bauwerke ganzheitlich zu betrachten, also unter ökologischen, ökonomischen und soziokulturellen Gesichtspunkten. Dies bedeutet einen Paradigmenwechsel für das Bauwesen.

Vom Österreichischen Stahlbauverband wurde 2003 eine Vorstudie mit dem Ziel in Auftrag gegeben, Stärken und Schwächen des Stahlbaus unter den neuen Rahmenbedingungen zu erheben und daraus Chancen und künftige Handlungsfelder für den Stahlhochbau abzuleiten. Es wurde untersucht, wo die Stahlskelettbauweise in bezug auf die ökologische Nachhaltigkeit im Vergleich zu Konkurrenzbauweisen liegt. Die ökologische Bewertung wurde mit dem Instrument der Ökobilanz gemäß ÖNORM EN ISO 14040 [25] durchgeführt. Ergebnis daraus ist eine Darstellung der Stahlskelettbauweise im Vergleich zur Holzskelett‐ und Stahlbetonbauweise. Aspekte der Rezyklierbarkeit oder Demontierbarkeit, also der Kreislauffähigkeit, sind mit den derzeitigen Ökobilanzen nicht abzubilden. Zudem zeigte sich, daß Vergleiche auf Produkt‐ oder Gebäudeebene zu verzerrten Ergebnissen führen können, da die zur Verfügung stehenden ökologischen Basisdaten unterschiedlicher Datenbanken große Schwankungsbreiten aufweisen. Im Rahmen dieser Arbeit konnten die ökologischen Kennwerte von Elektrostahl erheblich verbessert werden.
Alcohol sclerotherapy for successful treatment of focal adenomyosis: a case report
Authors: Furman B. , Appelman Z. , Hagay Z. , Caspi B.
Published: March 2007

Adenomyosis is characterized by the presence of ectopic endometrial tissue within the myometrium. Treatment options range from use of non‐steroidal anti‐inflammatory drugs and hormonal suppression for symptomatic relief, to endometrial ablation or even hysterectomy. We report a case of successful ultrasound‐guided aspiration of focal adenomyosis with intracavitary alcohol instillation in a patient with a recurrent intramural uterine lesion. This is the first report of the treatment of sclerotherapy by alcohol instillation, which may be considered as a reasonable alternative modality in treating rare cases of symptomatic adenomyosis. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Sonohysterographic endometrial sampling and hysteroscopic endometrial biopsy: a comparative study
Authors: Leone F. P. G. , Carsana L. , Lanzani C. , Vago G. , Ferrazzi E.
Published: March 2007

Objectives

To compare the quantity and quality of endometrial tissue sampled at saline contrast sonohysterography (SCSH) with that obtained by directed endometrial biopsy by operative hysteroscopy in patients with diffusely thickened and/or inhomogeneous endometrium at SCSH. A secondary aim was a comparison of the extent of procedure‐related pain.

Methods

One hundred and twenty‐eight patients with diffusely thickened (> 4 mm) and/or inhomogeneous endometrium at SCSH were prospectively recruited. Endometrial sampling was performed at the end of SCSH using the same 4.7‐mm intrauterine catheter that had been used for saline instillation. These samples were compared to directed endometrial biopsies obtained with the guidance of an office 5‐mm hysteroscope. After hysteroscopy, an extended guided curettage was performed under general anesthesia, providing specimens that were considered the gold standard for histological diagnosis. Endometrial specimen area (mm2), histologic concordance and procedure related pain (10‐cm VAS) were compared for the two techniques.

Results

The median age of 88 pre‐ and of 40 post‐menopausal patients was 41 (interquartile range, 34–48) years and 57 (interquartile range, 52–67) years, respectively. The median area of endometrial specimen obtained by SCSH was 25.1 (interquartile range, 12.4–52.3) mm2 and was not significantly different from that obtained by hysteroscopy (16.9 (interquartile range, 10.0–52.7) mm2). The K values of the two different techniques for typical hyperplasia (n = 61) and for premalignant and malignant lesions (n = 26) were 0.91 and 0.94, respectively. Procedure‐related pain was not significantly different between pre‐ and postmenopausal patients for both sampling techniques.

Conclusions

SCSH with sampling proved to be as good as and as tolerable as hysteroscopic biopsy in cases with diffusely thickened and/or inhomogeneous endometrium. Both these imaging and biopsy techniques should be considered a reliable outpatient procedure in the management of patients with abnormal uterine bleeding. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Development of confocal 3D micro‐XRF spectrometer with dual CrMo excitation
Authors: Tsuji Kouichi , Nakano Kazuhiko
Published: March 2007

A new 3D micro‐XRF instrument based on a confocal setup using two independent polycapillary x‐ray lenses and two x‐ray sources (Cr and Mo targets) was developed. A full polycapillary x‐ray lens was attached to each x‐ray tube. Another half polycapillary lens was attached to a silicon drift x‐ray detector (SDD). The focal spots of the three lenses were adjusted to a common position. The depth resolutions that were evaluated by use of a 10‐µm thick Au foil were approximately 90 µm for the x‐ray energy of Au Lα. The effects of the dual Cr–Mo x‐ray beam excitation were investigated. It was confirmed that the XRF intensity of light elements was increased by applying the Cr‐target x‐ray tube in a confocal configuration. In the proposed confocal configuration, 3D elemental mapping of the major elements of an amaranth seed was performed nondestructively at ambient air pressure. Each element of the seed showed different mapping images in the different depth layers. Copyright © 2007 John Wiley & Sons, Ltd.
On the stability of quasi‐static paths for finite dimensional elastic‐plastic systems with hardening
Authors: Martins J.A.C , Monteiro Marques M.D.P , Petrov A.
Published: March 2007

In this paper we prove the stability of quasi‐static paths of finite dimensional mechanical systems that have an elastic‐plastic behavior with linear hardening. The concept of stability of quasi‐static paths used here is essentially a continuity property relatively to the size of the initial perturbations (as in Lyapunov stability) and to the smallness of the rate of application of the external forces (which plays here the role of the small parameter in singular perturbation problems). The discussion of stability is preceded by the presentation of mathematical formulations (plus existence and uniqueness results) for those dynamic and quasi‐static problems, in a form that is convenient for the subsequent discussion of stability.
Ecological function losses caused by monotonous land use induce crop raiding by wildlife on the island of Yakushima, southern Japan
Authors: Agetsuma Naoki
Published: March 2007

Mass production is a logical outcome of price competition in a capitalist economy. It has resulted in the need for large‐scale logging and planting of commercial crops. However, such monotonous land use, or monoculture, has damaged various ecological functions of forests and eroded the beneficial public service provided by forests. In Japan, the most widespread monotonous land use is associated with coniferous plantations, the expansion of which was encouraged by Forest Agency policies from 1958 that were aimed at increasing wood production. By 1986, half of all forested lands had been transformed into single‐species conifer plantations. These policies may damage the ecological functions of forests: to provide stable habitats for forest wildlife. In particular, food supplies for wildlife have fluctuated greatly after several decades of logging. Some species have therefore changed their ecology and begun to explore novel environments proactively in order to adapt to such extreme fluctuations. Such species have started to use farmlands that neighbor the plantations. In this sense, crop raiding by wildlife can be regarded as a negative result of monotonous land use due to the loss of ecological functions. Therefore, habitat management to rehabilitate ecological functions and to reorganize the landscape will be required in order to resolve the problem of crop raiding by wildlife. This study examines crop raiding by Japanese deer (Cervus nippon) and monkeys (Macaca fuscata) on the island of Yakushima, which typifies crop‐raiding situations in Japan.