bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractA 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

AbstractDiffusion 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

AbstractIn 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

AbstractObjectiveThe prenatal genetic diagnosis and counseling of oculocutaneous albinism type II (OCA2) by detecting mutations in the OCA2 geneMethodsDNA 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.ResultsCase 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.ConclusionThis 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

AbstractOccipital 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

AbstractWe 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

AbstractLong‐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

AbstractThe 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

AbstractDetermination 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

AbstractElastic 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

AbstractA 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

AbstractThe 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

AbstractMost 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

AbstractBy 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

AbstractAn 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractAn 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

AbstractRunner 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

AbstractTwo 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

AbstractComparisons 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

AbstractProteasomes 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.