bluuebunny/crossref_metadata_2025_split huggingface dataset:
Health‐status of adult survivors of childhood cancer: A large‐scale population‐based study from the British childhood cancer survivor study
Authors: Reulen Raoul C. , Winter David L. , Lancashire Emma R. , Zeegers Maurice P. , Jenney Meriel E. , Walters Stephen J. , Jenkinson Crispin , Hawkins Mike M. 
Published: April 2007

AbstractThe purpose of this study was to investigate the effect of childhood cancer and its treatment on self‐reported health‐status in 10,189 adult survivors of childhood cancer in Britain. Age‐ and sex‐adjusted scores on the SF‐36 Mental and Physical Component Summary scales (MCS, PCS, respectively) were compared between survivors and UK norms, and between subgroups of survivors, by multiple regression. Survivors had comparable scores to UK‐norms on the MCS scale (difference (D) = −0.1, 99% CI: −0.5, 0.3). The difference in scores between survivors and UK‐norms on the PCS scale varied by age (pheterogeneity < 0.001). Young survivors (16–19 years) scored similarly to UK‐norms (D = 0.5, (−1.1, 2.2), whereas the age groups of 25 and older scored statistically and clinically significantly below UK‐norms (all p‐values < 0.0001), with Ds ranging between −2.3 (−3.5, −1.2) and −3.7 (−5.0, −2.4). Survivors of central nervous system (CNS) and bone tumors scored significantly (p‐value at all ages <0.003) below UK‐norms on the PCS scale. Specifically, these survivors were substantially more limited in specific daily activities such as, for example, walking a mile (40, 63%, respectively) when compared to UK‐norms (16%). In conclusion, childhood cancer survivors rate their mental health broadly similarly to those in the general population. Survivors of CNS and bone tumors report their physical health‐status to be importantly below population norms. Although self‐reported physical health is at least as good as in the general population among young survivors, this study suggests that perceived physical health declines more rapidly over time than in the general population. © 2007 Wiley‐Liss, Inc.
Quantum chemical investigation of hydrogen‐bond strengths and partition into donor and acceptor contributions
Authors: Raub Stephan , Marian Christel M. 
Published: April 2007

AbstractWe present a simple increment model for use in the rapid scoring of hydrogen bond strengths employing 15 chemically diverse donor and 28 acceptor terms. The increments cover a large variety of hydrogen bond donor and acceptor groups and are more specific than SYBYLatom types. The increments have been fitted to quantum chemicalab initiointeraction energies of 81 small hydrogen‐bonded complexes determined at the level of second‐order Møller‐Plesset perturbation theory (MP2). The complexes have been chosen such as to represent the most important types of donor‐acceptor pairs found in biological systems. Sulphur is found to be a strong hydrogen bond acceptor while its donor capacities are weak. By taking CH acidic H donors into account, a linear correlation between MP2 energies and the increment model with a coefficient of correlation ofr2= 0.994 has been accomplished. The transferability of the fitted parameters has been assessed on a second set of complexes including larger molecules of biological relevance. Very good agreement has been achieved for noncyclic hydrogen bonds. Cooperative effects are not accounted for by the current increment model. For this reason, binding energies of strong cyclic hydrogen bonds, as e.g. present in DNA base pairs, are underestimated by about 30–40%. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Calculating rate constants with updated Hessians using variational transition state theory with multidimensional tunneling
Authors: Chuang Yao‐Yuan 
Published: April 2007

AbstractVariational transition state theory with multidimensional tunneling (VTST/MT) has been used for calculating the rate constants of reactions. The updated Hessians have been used to reduce the computational costs for both geometry optimization and trajectory following procedures. In this paper, updated Hessians are used to reduce the computational costs while calculating the rate constants applying VTST/MT. Although we found that directly applying the updated Hessians will not generate good vibrational frequencies along the minimum energy path (MEP), however, we can either re‐compute the full Hessian matrices at fixed intervals or calculate the Block Hessians, which is constructed by numerical one‐side difference for the Hessian elements in the “critical” region and Bofill updating scheme for the rest of the Hessian elements. Due to the numerical instability of the Bofill update method near the saddle point region, we have suggested a simple strategy in which we follow the MEP until certain percentage of the classical barrier height from the barrier top with full Hessians computed and then performing rate constant calculation with the extended MEP using Block Hessians. This strategy results a mean unsigned percentage deviation (MUPD) around 10% with full Hessians computed till the point with 80% classical barrier height for four studied reactions. This proposed strategy is attractive not only it can be implemented as an automatic procedure but also speeds up the VTST/MT calculation via embarrassingly parallelization to a personal computer cluster. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
The effect of Ginkgo biloba on the cerebellum of aging SAMP mouse—A TUNEL, bcl‐2, and fMRI study
Authors: Wai Maria S.M. , Rudd John A. , Chan W.Y. , Antonio Gregory E. , Yew David T. 
Published: April 2007

AbstractEGb 761, an extract from Ginkgo biloba that possesses neuroprotective properties, was fed to a strain of fast aging mice (SAMP‐8) beginning at 3 weeks of age until they were sacrificed at 3 months and 11 months, respectively, along with an age‐matched control group without herbal feeding. The aim of the study was to determine (1) the status of apoptosis and the status of bcl‐2, a molecule involved in the fate of cells following injury, in the cerebella of these mice and (2) to analyze the functional changes as shown by fMRI images. The data indicated that there were no differences in apoptosis between the mice fed with EGb 761 and the control group at the two time points of 3 and 11 months of age. For bcl‐2 positive cells, there was a decrease in density only in the cerebella of 11‐month‐old mice fed with the herbal extract when compared with controls. Functional studies indicated that while no changes were observed in the 3‐month‐old mice fed with Ginkgo biloba, an expansion of activated sites, possibly related to “synaptic reorganization and pathway alteration,” was observed in the 11‐month‐old mice. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Development of strategies for conditional RNA interference
Authors: Allen Danny , Kenna Paul F. , Palfi Arpad , McMahon Helena P. , Millington‐Ward Sophia , O'Reilly Mary , Humphries Pete , Farrar G. Jane 
Published: April 2007

AbstractBackgroundRNA interference (RNAi) represents a powerful tool with which to undertake sequence‐dependent suppression of gene expression. Synthesized double‐stranded RNA (dsRNA) or dsRNA generated endogenously from plasmid or viral vectors can be used for RNAi. For the latter, polymerase III promoters which drive ubiquitous expression in all tissues have typically been adopted. Given that dsRNA molecules must contain few 5′ and 3′ over‐hanging bases to maintain potency, employing polymerase II promoters to drive tissue‐specific expression of RNAi may be problematic due to potential inclusion of nucleotides 5′ and 3′ of siRNA sequences.MethodsTo circumvent this, polymerase II promoters in combination with cis‐acting hammerhead ribozymes and short‐hairpin RNA sequences have been explored as a means to generate potent dsRNA molecules in tissues defined by the promoter in use.ResultsThe novel constructs evaluated in this study produced functional siRNA which suppressed the enhanced green fluorescent protein (eGFP) both in vitro and in vivo (in mice). Additionally, the constructs did not appear to elicit a significant type‐1 interferon response compared to traditional H1‐transcribed shRNA.ConclusionsGiven the potential ‘off‐target’ effects of dsRNAs, it would be preferable in many cases to limit expression of dsRNA to the tissue of interest and moreover would significantly augment the resolution of RNAi technologies. Notably, the system under evaluation in this study could readily be adapted to achieve this objective. Copyright © 2007 John Wiley & Sons, Ltd.
Strategy as a configuration of activities: evidence that strategy absence exists
Authors: Rodwell John J. , Shadur Mark A. 
Published: April 2007

Abstract

Qualitative content analysis on company documents is used to inductively operationalize strategy as a configuration of activities in medium and large companies in the Australian information technology industry.

Three specific configurations were found: Global Exporters, Flexible Scanners and Drifters. The Global Exporters and Flexible Scanners have similarities with prior strategy types. In contrast, the Drifters provide evidence for the concept of strategy absence. The configurations found highlight the value of considering strategic change in terms of quantum change.

Copyright © 2007 John Wiley & Sons, Ltd.
Rapid evaluation and discrimination of γ‐irradiated carbohydrates using FT‐Raman spectroscopy and canonical discriminant analysis
Authors: Kizil Ramazan , Irudayaraj Joseph 
Published: April 2007

AbstractChemical changes induced by gamma irradiation of selected sugar systems—honey and fructose—were investigated through their molecular fingerprint using Fourier transform Raman spectroscopy (FT‐Raman). Generalized two‐dimensional (2‐D) correlation spectroscopy was applied to FT‐Raman spectra of the control and 17 kGy irradiated fructose to elucidate changes in the chemical structure upon irradiation. The irradiation induced changes in the ring (below 700 cm−1) and conformational structure (800–1500 cm−1) of fructose were identified by means of a 2‐D FT‐Raman correlation spectroscopy. The irradiation damage depicted from the CH stretch region (2800–3000 cm−1) of the FT‐Raman spectra of honey was used to develop a pattern recognition model for classifying honey based on the irradiation dose. A hybrid partial least squares (PLS)–canonical variate analysis (CVA) with the optimum number of factors from PLS was used for rapid discrimination of honeys irradiated at 1, 5, 10 or 17 kGy. The present study demonstrated that FT‐Raman spectroscopy, together with chemometrics, could be a rapid tool for classification of foodstuffs with high sugar content and provides a viable option to explore radiation‐induced modifications to sugar systems subjected to irradiation processing. Copyright © 2007 Society of Chemical Industry
On the mathematical model of a viscoelastic bar
Authors: Takači Arpad , Takači Djurdjica 
Published: April 2007

AbstractIn this paper we consider a mathematical model describing the shock of a rigid body and a linear viscoelastic bar, resting on a rigid base, in the frames of the Mikusiński operator calculus. We determine and analyse the character of the exact solution of the corresponding problem in the field of Mikusiński operators. We construct an approximate solution of this problem, and estimate the error of approximation. The mentioned problem is taken from the papers (J. Mech. NCSR Vietnam Tom 1991; 13(2):1–7; Nonlinear Anal. Theory Meth. Appl. 2001; 43:547–561). Copyright © 2007 John Wiley & Sons, Ltd.
A numerical–analytical combined method for vibration of a beam excited by a moving flexible body
Authors: Ouyang Huajiang , Mottershead John E. 
Published: April 2007

AbstractThe vibration of a beam excited by a moving simple oscillator has been extensively studied. However, the vibration of a beam excited by an elastic body with conformal contact has attracted much less attention. This is the subject of the present paper. The established model is more complicated but has a much wider range of applications than the moving‐oscillator model.Because the moving body is flexible, the moving loads at the contact interface are not known a priori and must be determined together with the dynamics of the whole system. In this paper, the equation of motion of the beam and the moving body are established separately using a numerical–analytical combined approach. It is found from the numerical results of the simulated example that the vibrations of the moving body and the beam excited by the moving body are significantly influenced by the travelling speed. At very low or very high speeds the dynamic effect is small and the beam deforms to take the shape of its static deflection. Vibrations tend to be greater in the intermediate speed range and the total moving force at the interface of the beam and the moving body can be compressive and tensile. Copyright © 2007 John Wiley & Sons, Ltd.
Evidence of two distinct mechanisms for CC or CO bond formation in the oxidative coupling of phenols
Authors: Roubaty J. L. , Revillon A. 
Published: March 2007

AbstractThe oxidation of 2, 6‐xylenol by oxygen, catalysed by a copper complex, leads to poly‐phenylene ether or quinones according to the amount of added pyridine. The first oxidation step is common in the two processes giving aryloxy radicals. The pH of the medium plays a fundamental role so that at low values a second electron is removed and the diradical rearranges into a cation in acidic medium. This cation may add to the monomer or to H2O thus explaining the production of several quinones. It has been shown that in methanol solvent, a nucleophilic reagent, addition to the cation takes place giving a new product which was characterised by thin layer chromatography (tlc).
Glass transition temperatures of poly N — (N — alkyl)—maleimides
Authors: Barrales‐Rienda J. M. , Gonz Ramos J. Ález , Chaves M. Sánchez 
Published: March 2007

AbstractThe glass transition temperatures (Tgs) of a series of poly N‐(n‐alkyl) maleimides covering only the even members with side chains ranging in length from ethyl to n‐octadecyl have been studied from room temperature to above Tg. Tgs and thermal quantities have been determined from the specific volume‐temperature relations only for the higher (n=8, 10, 12, 14, 16 and 18, where n = no of CH2) members of the series. However for the lower ones (n = 2, 4, 6, 8 and 10) Tgs have been detected from heat capacity‐temperature traces of differential scanning calorimetry diagrams by extrapolation to zero rate of heating. Accurate consistency was found in the values (n = 8 and 10) determined by both experimental methods.TgS of these polymers continuously decrease as the number of methylene groups in the side chain is increased, and they have been correlated with the size of the n‐alkyl group in the side chain. The results are in accord with a previously studied series concerning the effect of a long side chain on the Tg of a comb‐like polymer in the amorphous state.Tgs of poly N‐(n‐alkyl) maleimides encompassing a wide range of methylene group content (n = 2, 4, 6, 8, 10 and 12) have been examined according to the Gordon‐Taylor‐Wood extrapolation with the objective of ascertaining the Tg of polyethylene (PE). Our approach of ignoring higher members of the homologous series in this extrapolation appears to be old and well known and it has been variously ascribed to different authors. Extrapolation of Tg values to 100% amorphous PE gives a Tg of 200/pm 10 °K in complete agreement with recent predictions made by Boyer from different sources of data.The Simha‐Boyer free volume quantity Δa. Tg decreases slowly with the methylene group content in the longer terms (n = 8, 10, 12, 14, 16 and 18) of the series presumably because of a reduction in the polarity or an in‐chain crankshaft loss mechanism which generates free volume in the glassy state, as stated by Boyer.Tgs do not correlate very well with the contributions of the atomic groups to the cohesive energy density (c.e.d.) so it can be concluded that c.e.d. is not the only factor determining Tg. However, a somewhat improved relationship might be obtained by taking into account the steric hindrance effect according to an approach made by Hayes.
The reactivity of 2‐furaldehyde and its derivatives in polymerisation reactions involving the carbonyl bond
Authors: Gandini Alessandro , Rieumont Jacques 
Published: March 2007

AbstractThe homopolymerisation of 2‐furaldehyde, 5‐methyl‐2‐furaldehyde and 2‐furyl methyl ketone and their cationic copolymerisation (BF3. Et2) with olefins were investigated. All attempts to obtain homopolymers failed because of thermodynamic restrictions. 2‐Furaldehyde and α‐methylstyrene gave an alternating copolymer of low degree of polymerisation, 2‐methyl‐2‐furaldehyde and α‐methylstyrene gave copolymers rich in 5‐methyl‐2‐furaldehyde, indicating a penultimate effect in the growth mechanism. The use of less basic comonomers (cyclopentadiene, styrene, isoprene, etc.) resulted in inhibition or strong retardation of the polymerisation. The use of more basic comonomers (acenaphthy‐lene, N‐vinylcarbazole) resulted in their homopolymerisation. Furyl methyl ketone inhibited the polymerisation of all comonomers tried. A complex between BF3. Et2O and 2‐furaldehyde was isolated and characterised. A general mechanism is offered to explain the behaviour of these systems.
Effect of thermal stresses on the dynamic moduli of abs‐resins
Authors: Booij H. C. 
Published: March 2007

AbstractThe magnitude of the thermal stresses generated among the polymeric constituents in highly grafted ABS‐samples during cooling down from the melt can be calculated by means of the ‘double emulsion model’. The effect of these stresses on the location of the rubber maximum in the loss modulus vs temperature plot can be derived from literature data regarding the pressure dependence of mechanical relaxation times.The results are in good agreement with those of torsion pendulum tests on a series of ABS‐samples prepared by blending a grafted rubber with various amounts of SAN‐resin. A continuous shift of the rubber loss peak to lower temperatures with decreasing rubber content is observed.Samples of low rubber content show a split damping peak at low temperatures. The area under the extra peak can be reversibly enlarged or reduced by varying the rate of cooling of the sample in the high temperature region, which indicates that real fracturing of graft molecules cannot be held responsible for this splitting of the peak.Especially at low rubber contents it has been found that the relative increase in rigidity with decreasing temperature is smaller in ABS‐resins than in the pure SAN‐copolymer. This decrease in relative modulus can also be correlated with the absolute value of the thermally induced hydrostatic tension.
Some peculiarities of gel chromatography of non‐modified cellulose on inorganic gels in cadoxen
Authors: Berek Duš , Katuščáková Gabriela , Novák Ivan 
Published: March 2007

AbstractThe possibilities and limitations of gel chromatography of non‐modified cellulose on inorganic supports in the complex solvent cadoxen are shown. The GPC fractionation in this system is possible but the evaluation of the analytical data would be rather complicated. The general problems of application of mixed eluents in gel chromatography are discussed.
Liquid multi‐phase separation in solvent‐polymer systems
Authors: Chermin H. A. G. 
Published: March 2007

AbstractIn Simple Flory‐Huggins solvent‐polymer systems liquid three‐phase separation occurs via a homogeneous double plait point. The conditions for three‐phase separation in a system consisting of a solvent and two polydisperse polymer homologues are given.It is shown that in a simple Flory‐Huggins solvent‐polymer system four and more phase separation cannot occur.General conditions for a multicritical point are given.
The Influence of Anionic Surfactant on the Stability of Styrene — Acrylonitrile Copolymer Latices
Authors: Ono Hiroshi , Jidai Eiki , Shibayama Kyoichi 
Published: April 2007

AbstractStyrene — acrylonitrile copolymer latices were prepared by emulsion polymerisation using sodium lauryl sulphate as emulsifier and potassium persulphate as initiator. The effect of sodium lauryl sulphate on the stability of these copolymer latices has been investigated using magnesium chloride as flocculating agent by measuring the rates of flocculation in the presence of various concentrations of surfactant. The values of the critical coagulation concentration (ccc) were found to increase with increasing sufactant concentration for all latices.The rates of increase in ccc with increasing surfactant concentrations were found to be almost independent of the content of acrylonitrile in the latex particles. The electrophoretic behaviour of these latices in the presence of the ionic surfactant has also been studied. The values of mobilities at ccc were found to decrease slightly with increase in the concentration of the ionic surfactant.
Crystallisation Studies of Trimethylhexamethylene/Hexamethylene Terephthalate Copolymers and Polystyrene Blends
Authors: Sheldon Ronald P. , Wrightson Ian 
Published: April 2007

AbstractA study has been made of the influence of the non‐crystallising component, trimethyl‐hexamethylene terephthalate, on the crystallisation behaviour of crystallising component, hexamethylene terephthalate in a series of their copolymers. It was found, using Differential Scanning Calorimetry, that as the melting point decreased with composition, the level of crystallinity fell more rapidly than expected on a proportionality basis, the degree of supercooling increased, and there was the emergence of a double crystallisation process. A second study in which the polymers were blended with polystyrene revealed similar influences but with less supercooling.
Problems with Polymers in Dentistry
Authors: Grant Alan 
Published: April 2007

AbstractDespite the important contributions made by polymers in dental treatment procedures, many shortcomings of these materials are apparent. Rigid type denture base polymers (commonly P.M.M.A.) have low impact and abrasion resistance and lack radiopacity. Resilient polymers used as denture liners may bond poorly to the denture base and suffer changes in physical properties in use. Early problems of colour stability, high polymerisation and thermal contraction, low surface hardness and poor abrasion resistance of the first polymeric filling materials have been only partly overcome by the introduction of polymer/ceramic composites.In dental cement applications, present bonding systems include unfilled dimethacrylates, which do not attach to dentine. A system based on polyacrylic acid, or copolymers thereof, is believed to bond chemically to the calcium in tooth structure, but the bond to dentine is poorer than that to enamel and also the hydrolytic stability is suspect.
Polymeric Inserts and Implants for the Controlled Release of Drugs
Authors: Graham Neil B. 
Published: April 2007

AbstractBecause of the ability of polymers to exist in glassy, rubbery or solvent‐swollen forms which have very different diffusion coefficients they are able to be used very effectively to control the release of incorporated drugs. As the polymers can vary from inert in vivo to biodegradable an even greater scope for versatile formulation is provided. The various parameters governing the design of controlled release implants are discussed.