bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examining the collision‐induced decomposition spectra of ammoniated triglycerides as a function of fatty acid chain length and degree of unsaturation. I. The OXO/YOY series
Authors: Li Xingwen , Evans Jason J. 
Published: August 2005

AbstractA series of positionally pure triglycerides (TAGs) of the form OXO and YOY, where O is the oleate moiety and X and Y are large arrays of different fatty acid moieties, was synthesized and analyzed by reversed‐phase high‐performance liquid chromatography/tandem mass spectrometry. The intensities of the collision‐induced decomposition (CID) products of ammoniated TAGs (ammonium ion adducts) were examined as a function of chain length, degree of unsaturation, double‐bond position, and cis/trans configuration of X and Y. The major CID products, the diglyceride fragment ions and the MH+ ion, were plotted as functions of chain length for the saturated and mono‐unsaturated series of X and Y. Different trends for each of these series were observed. Trends in the abundances of these fragment ions were also characterized as a function of degree of unsaturation in the TAGs. In general, the fractional abundances of the MH+ ions vary linearly with degree of unsaturation. However, the presence of double bonds positioned close to the carbonyl carbon of the fatty acid chain promotes the formation of the diglyceride fragment ion corresponding to loss of that fatty acid. Mechanisms of the formation and decomposition of ammoniated TAGs are proposed that fit the trends observed in the data. Extensions of this work are described, and a vision of a derived library of CID spectra is discussed as a platform for comprehensive analysis of complex TAG mixtures. Copyright © 2005 John Wiley & Sons, Ltd.
Use of monoatomic and polyatomic projectiles for the characterisation of polylactic acid by static secondary ion mass spectrometry
Authors: Boschmans Bart , Van Royen Pieter , Van Vaeck Luc 
Published: August 2005

AbstractThe application of polyatomic primary ions is a strongly developing branch of static secondary ion mass spectrometry (S‐SIMS), since these projectiles allow a significant increase in the secondary ion yields to be achieved. However, the different limitations and possibilities of certain polyatomic primary ions for use on specific functional classes of samples are still not completely known. This paper compares the use of monoatomic and polyatomic primary ions in S‐SIMS for thin layers of polylactic acid (PLA), obtained by spin‐coating solutions on silicon wafers. Bombardment with Ga+, Xe+ and SF primary ions allowed the contribution of the projectile mass and number of atoms in the gain in ion yield and molecular specificity (relative importance of high m/z and low m/z signals) to be assessed. Samples obtained by spin‐coating solutions with increasing concentration showed that optimal layer thickness depended on the primary ion used. In comparison with the use of Ga+ projectiles, the yield of structural ions increased by a factor of about 1.5 to 2 and by about 7 to 12 when Xe+ and SF primary ion bombardment were applied, respectively. A detailed fragmentation pattern was elaborated to interpret ion signal intensity changes for different projectiles in terms of energy deposition and collective processes in the subsurface, and the internal energy of radical and even‐electron precursor ions. Copyright © 2005 John Wiley & Sons, Ltd.
Nitrogen balance and δ15N: why you're not what you eat during nutritional stress
Authors: Fuller Benjamin T. , Fuller James L. , Sage Nancy E. , Harris David A. , O'Connell Tamsin C. , Hedges Robert E. M. 
Published: August 2005

AbstractWhile past experiments on animals, birds, fish, and insects have shown changes in stable isotope ratios due to nutritional stress, there has been little research on this topic in humans. To address this issue, a small pilot study was conducted. Hair samples from eight pregnant women who experienced nutritional stress associated with the nausea and vomiting of morning sickness (hyperemesis gravidarum) were measured for carbon (δ13C) and nitrogen (δ15N) stable isotope ratios. The δ13C results showed no change during morning sickness or pregnancy when compared with pre‐pregnancy values. In contrast, the δ15N values generally increased during periods of weight loss and/or restricted weight gain associated with morning sickness. With weight gain and recovery from nutritional stress, the hair δ15N values displayed a decreasing trend over the course of gestation towards birth. This study illustrates how δ15N values are not only affected by diet, but also by the nitrogen balance of an individual. Potential applications of this research include the development of diagnostic techniques for tracking eating disorders, disease states, and nitrogen balance in archaeological, medical, and forensic cases. Copyright © 2005 John Wiley & Sons, Ltd.
Electronic substituent effects in the electron impact mass spectrometry of 2‐(arylazo)‐4‐phenylphenols
Authors: Pérez‐Caballero Guadalupe , Jiménez‐Cruz Federico , Matamoros Pablo Hernández , García José Guadalupe , Cortés‐Guzmán Fernando , Miranda René 
Published: August 2005

AbstractA mass spectrometric study of a set of six novel 2‐(arylazo)‐4‐phenylphenols 1–6 was performed. The electron impact spectra were acquired and analyzed for five of the compounds in order to establish a fragmentation pattern. The suggested pathways were investigated and confirmed by means of tandem mass spectrometry (MS/MS) experiments together with high‐resolution accurate mass data. However, the sixth molecule, a sodium sulfonate salt, was studied using fast atom bombardment (FAB) ionization in positive and negative modes. In addition, some electronic substituent effects were investigated by analyzing Hammett‐McLafferty linear free energy correlations for some peaks derived from the corresponding molecular ions. Also, the role of the OH · · · N hydrogen bond present in the target compounds was analyzed. The roles of these Hbonds were consistent with the corresponding acidity constant values obtained experimentally as well as by theoretical quantum chemistry calculations using HF/6‐31 + G(d,p) and B3LYP/6‐31G(d,p). Some spectrometric data were correlated with topological properties derived from the atoms‐in‐molecules (AIM) theory. Copyright © 2005 John Wiley & Sons, Ltd.
Electrospray tandem mass spectrometry of new porphyrin amino acid conjugates
Authors: Serra V. Vaz , Domingues M. R. M. , Faustino M. A. F. , Domingues P. , Tomé J. P. C. , Neves M. G. P. M. S. , Tomé A. C. , Cavaleiro J. A. S. , Ferrer‐Correia A. J. 
Published: August 2005

AbstractPorphyrin amino acid conjugates with one or two porphyrin units were analyzed by electrospray ionization tandem mass spectrometry (ESI‐MS/MS). The ESI‐MS spectra of all the porphyrins studied, obtained in positive ion mode, show the presence of the corresponding protonated molecule [M+H]+; ESI‐MS spectra of diporphyrinyl compounds also show the doubly charged ions [M+2H]2+. The fragmentations of these ions induced by collision with argon were studied (ESI‐MS/MS). ESI‐MS/MS gives detailed structural information about the amino acids associated with the porphyrin. Cleavage of the bonds in the vicinity of the porphyrin moiety and those involving the side chain of amino acid residues gives structural information about this type of association. A fragmentation common to all derivatives corresponds to the cleavage of the phenylCO bond. The expected cleavage of the amide bond, that links the porphyrin to the amino acid moiety, is a minor fragmentation, which in some cases is even absent. The MS/MS spectra of the monoporphyrinyl derivatives show product ions characteristic of the amino acid linked to the porphyrin; the fragmentation also indicates when the amino acids has a terminal carboxylic group or a terminal ester group. The fragmentations of the diporphyrinyl compounds occur mainly by the cleavage of the spacer, leading, in the case of the doubly charged ions, to predominantly mono‐charged ions, indicating a preferential location of the two protons in separated porphyrinic units. Copyright © 2005 John Wiley & Sons, Ltd.
A liquid chromatography/tandem mass spectrometry method for the simultaneous quantification of isoniazid and ethambutol in human plasma
Authors: Chen Xiaoyan , Song Bo , Jiang Hongjian , Yu Kate , Zhong Dafang 
Published: August 2005

AbstractIsoniazid and ethambutol are commonly used in various combination treatments for tuberculosis, and for this reason a rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for simultaneous quantification of these two drugs in human plasma. After a simple protein precipitation using methanol, the analytes and the internal standard metformin were chromatographed on a C18 column and detected by MS/MS. An atmospheric pressure chemical ionization interface was chosen to reduce ion suppression from sample matrix components and provide high sensitivity. The LC retention times for isoniazid and ethambutol were 2.46 and 2.27 min, respectively. The method was linear in the concentration range of 10.0–5000 ng/mL for each analyte using 100 µL plasma. The intra‐ and inter‐day precisions, expressed as the relative standard deviation (RSD), were less than 5.7 and 6.4%, determined from QC samples for isoniazid and ethambutol, and the accuracies were within ±2.1% and ±4.5% in terms of relative error, respectively. The method was successfully employed in a pharmacokinetic study after oral administration of a multicomponent formulation containing 150 mg isoniazid, 500 mg ethambutol, 150 mg rifampicin and 250 mg pyrazinamide. Copyright © 2005 John Wiley & Sons, Ltd.
‘All‐in‐One’ analysis for metabolite identification using liquid chromatography/hybrid quadrupole time‐of‐flight mass spectrometry with collision energy switching
Authors: Wrona Mark , Mauriala Timo , Bateman Kevin P. , Mortishire‐Smith Russell J. , O'Connor Desmond 
Published: August 2005

AbstractThe removal of bottlenecks in discovery stage metabolite identification studies is an ongoing challenge for the pharmaceutical industry. We describe the use of an ‘All‐in‐One’ approach to metabolite characterization that leverages the fast scanning and high mass accuracy of hybrid quadrupole time‐of‐flight mass spectrometry (QqToFMS) instruments. Full‐scan MS and MS/MS data is acquired using collision energy switching without the preselection, either manually or in a data‐dependent manner, of precursor ions. The acquisition of ‘clean’ MS/MS data is assisted by the use of ultrahigh‐performance chromatography. Data acquired using this method can then be mined post‐acquisition in a number of ways. These include using narrow window extracted ion chromatograms (nwXICs) for expected biotransformations, XICs for the product ions of the parent compound and/or expected modification of these product ions, and neutral loss chromatograms. This approach has the potential to be truly comprehensive for the determination of in vitro biotransformations in a drug discovery environment. Copyright © 2005 John Wiley & Sons, Ltd.
Identification of heat‐induced degradation products from purified betanin, phyllocactin and hylocerenin by high‐performance liquid chromatography/electrospray ionization mass spectrometry
Authors: Herbach Kirsten M. , Stintzing Florian C. , Carle Reinhold 
Published: August 2005

AbstractBetanin, phyllocactin (malonylbetanin) and hylocerenin (3‐hydroxy‐3‐methylglutarylbetanin) were isolated from purple pitaya (Hylocereus polyrhizus [Weber] Britton & Rose) juice, and their degradation products generated by heating at 85°C were subsequently monitored by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry. Thermal degradation of phyllocactin and hylocerenin in purified solution excluding the alleged protective effects by the juice matrix is reported for the first time. Betanin was predominantly degraded by hydrolytic cleavage, while decarboxylation and dehydrogenation were of minor relevance. In contrast, hylocerenin showed a strong tendency to decarboxylation and dehydrogenation, hydrolytic cleavage of the aldimine bond occurring secondarily. Phyllocactin degradation was most complex because of additional decarboxylation of the malonic acid moiety as well as generation and subsequent degradation of betanin due to phyllocactin demalonylation. Upon prolonged heating, all betacyanins under observation formed degradation products characterized by an additional double bond at C2C3. Hydrolytic cleavage of the aldimine bond of phyllocactin and hylocerenin yielded previously unknown acylated cyclo‐dopa derivatives traceable by positive ionization, while application of ESI(–) facilitated the detection of a glycosylated aminopropanal derivative and dopamine, which have never been described before as betanin degradation products. Copyright © 2005 John Wiley & Sons, Ltd.
Episodic gullying and paleomonsoon cycles on the Chinese Loess Plateau
Authors: Porter Stephen C. , An Zhisheng 
Published: August 2005

AbstractBuried gullies exposed in road excavations along the margin of a loess tableland on the Loess Plateau of central China lie within a thick loess-paleosol succession that spans ≥780,000 years. Constraining ages for gully cutting and filling are provided by dates of loess and soil units cut by and capping the paleogullies. An episode of gully cutting begins at the onset of an interglaciation and ceases as the gullies begin to fill with colluvium and airborne dust during the transition to full-glacial conditions. The episodic cutting and filling of gullies implies a basic astronomical (orbital) control of gully evolution involving cyclic changes in dominant summer and winter monsoon climates, surface hydrology, and vegetation cover.
Learning distributed leadership: part 2
Authors: Ross Lisa , Rix Mike , Gold Jeff 
Published: August 2005

PurposeThe second paper in a two‐paper series, this article seeks to consider how the ideas of cultural historical activity theory were used in a learning programme for managers to examine and apply leadership as a collective phenomenon usually referred to as distributed leadership.Design/methodology/approachThe main elements of the programme are presented along with examples of application by learners.FindingsA key learning point that stood out is the identification of the social, historical and cultural context of leadership, rather than being focused on an individual. As learners move from actions of individuals to the activity system as a whole, distributed leadership is considered as the exertion of influence that can be inspired, distorted, subverted or ignored.Practical implicationsActivity systems are understood to be multi‐voiced and multi‐layered, subject to disturbances and flux that result in tension, contradiction and paradox which need to be understood and utilised to find ways of improving organisation performance.Originality/valueA case study on the experience of learners attempting to consider distributed leadership is provided.
The 6Ds™
Authors: Terry Robert 
Published: August 2005

PurposeToday's executive education programmes must lend themselves to comprehensive evaluation and measurement, in order that return on investment can be clearly demonstrated in the boardroom. This requires a unique approach to programme design from the outset, providing scope to ensure that outcomes can be continually followed up, long after an event has taken place. This paper aims to examine proven methods used to achieve this objective, creating programmes that deliver proof of lasting results.Design/methodology/approachThis is the 6DsTM approach pioneered by Calhoun Wick and Roy Pollock of the Fort Hill Company, on the basis of research undertaken amongst 30,000 learners. This method focuses on instigating behavioural change interventions over many months. It has been shown to significantly improve return on investment in executive education.FindingsThe paper states the evidence for the effectiveness of this technique but also highlights the fact that the majority of programmes are still not designed with the long‐term evaluation of performance and behavioural change in mind.Originality/valueThe paper challenges the paradigm of the traditional two‐day workshop where the trainer is centre‐stage. It instead concentrates on a new and innovative approach where the learner's line manager is pivotal, and success is measured in terms of measurable improvements in business performance. It will be of interest to educators and purchasers of executive education programmes.
Diversity in the spotlight
Authors: McDougall Adrian 
Published: August 2005

PurposeThis paper aims to address the problems that diversity, by its nature, throws up for training professionals, and to highlight the various ways in which drama, as a learning tool, offers solutions to those problems.Design/methodology/approachThe theory of experiential learning forms the back‐bone of the arguments proposed by the paper, and has many applications in the development and assessment of groups and individuals. While it focuses on a technique called “forum theatre”, all forms of drama‐based learning are founded on the theory of “learning by doing”.FindingsThe findings of the paper focus on the benefits of illustrating learning points through drama; encouraging creative thinking, risk‐taking, empathy and the use of conflict in a simulated environment to examine issues from all points of view.Practical implicationsThese findings point to a need for an artistic and non‐directive approach to diversity training, one that is responsive to the sensitive and emotive nature of the subject. It also calls for organisations to encourage the embracing of differences within their workforces.Originality/valueThe learning points discussed offer a fresh perspective to diversity trainers. It suggests opportunities to address the root causes of prejudice without the risks that traditional training methods necessarily bring with them, and it is relevant to anyone involved in the design and delivery of diversity training.
Results of a survey into how people become managers and the management development implications
Authors: Rees W. David , Porter Christine 
Published: August 2005

PurposeTo establish how people become managers.Design/methodology/approachA survey of 50 managers carried out at the end of 2004 by students on the BA in Business and Management course at the University of Westminster. A total of 25 students chose two managers each to interview. Of the managers, 38 were from the UK.FindingsOut of 50 managers surveyed, 47 were specialists before they acquired management responsibilities. Only 12 received management training before becoming managers and that training was not always felt to be effective. The transition from specialist to becoming a manager of specialists was often stressful. Only two people became managers as a direct result of undertaking business studies degree programmes.Research limitations/implicationsSpecialists often acquire managerial responsibilities, and often quite early in their career. Those aspiring to management have found that their entry route is via a specialist department. Consequently, it is appropriate to see that managers have the right blend of specialist and managerial skills and that they are given help in adjusting to managerial roles. The implications of the specialist route into management needs to be reflected in the structure of increasingly popular undergraduate programmes in business studies. There is a case for such courses having both specialist options and a managerial component.Originality/valueThere is little research about how people become managers. It is particularly important that the specialist route identified is understood by those wishing to become managers, by universities and colleges running both business and specialist courses and by employers.
Are graduates equipped with the right skills in the employability stakes?
Authors: Raybould Joanne , Sheedy Victoria 
Published: August 2005

PurposeTo discuss employability and skills requirements for graduates from a graduate recruiter's point of view.Design/methodology/approachTo look at key graduate recruitment organisations and explain what skills programmes are available to graduates. Also looks at continued development and what employers may be able to do in the future to improve skills?FindingsThere are transferable skills that employers like to see in a graduate and these can vary according to type of role; also, in general, graduates are keen to develop their skills further. There are organisations to help graduates improve these employability skills like Graduate Advantage and higher education institutions.Originality/valueOf value to employers looking to recruit graduates, who need to be aware of what types of programmes are available to graduates. It is valuable to graduates, who need to look at their own skills and improve their employability.
How does dry contact occur in elastohydrodynamic lubrication?
Authors: Zhang Y. 
Published: August 2005

PurposeTo form and develop a new mode of mixed elastohydrodynamic lubrication (mixed EHL) which is more realistic and of more application values to a practical elastohydrodynamic contact on gears, cams and roller bearings than the previous and current existing mixed EHL models.Design/methodology/approachThe representative theoretical and experimental studies on elastohydrodynamic lubrication (EHL) and mixed EHL carried out in the previous and recent time, including those of the author, are reviewed. The obtained results on EHL and mixed EHL in those studies and the viewpoints on the mode of mixed EHL based on those results developed in those studies are compared and evaluated. Strong proves are formed on the new mode of mixed EHL proposed in the present paper based on these comparisons and evaluations.FindingsStrong viewpoints are formed on the mode of the occurrence of dry contact in EHL in a practical concentrated contact. A new mode of mixed EHL is proposed by incorporating this mode of the occurrence of dry contact in EHL. Also, comments and evaluations on the previous researches on mixed EHL are made.Practical implicationsA very useful material for the engineers who are engaged in the design of EHL on gears, cams and roller bearings, and for the tribology scientists who thrust efforts in studying EHL and mixed EHL both by theoretical modeling and by experiments.Originality/valueA new mode of mixed EHL is originally proposed by incorporating the finding of a more realistic mode of the occurrence of dry contact in EHL. This new mode of mixed EHL should become the direction of the theoretical research of mixed EHL in the future time. It provides a clearer way to this research.