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Articles 31 - 60 of 87

Full-Text Articles in Social and Behavioral Sciences

Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon Jul 2013

Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon

Professor Nick E Dixon

Changes in protein conformation are thought to alter charge state distributions observed in electrospray ionization mass spectra (ESI-MS) of proteins. In most cases, this has been demonstrated by unfolding proteins through acidification of the solution. This methodology changes the properties of the solvent so that changes in the ESI-MS charge envelopes from conformational changes are difficult to separate from the effects of changing solvent on the ionization process. A novel strategy is presented enabling comparison of ESI mass spectra of a folded and partially unfolded protein of the same amino acid sequence subjected to the same experimental protocols and conditions. …


Geochemical Consequences Of The Permian-Triassic Mass Extinction In A Non-Marine Succession, Sydney Basin, Australia, M Williams, B Jones, P Carr Jun 2013

Geochemical Consequences Of The Permian-Triassic Mass Extinction In A Non-Marine Succession, Sydney Basin, Australia, M Williams, B Jones, P Carr

B. G. Jones

The identification of the Permian–Triassic boundary (PTB) and Permian–Triassic mass extinction event (PTME) in eastern Australia is based primarily on palynological and plant fossil evidence with limited δ13Corg data from the northern part of the Sydney Basin. Consequently, the PTB in the Sydney Basin has been placed at the top of the last Permian coal measures. Here we report carbon and nitrogen isotopic data, together with major element, trace element and mineralogical data, for a continuous non‐marine Permian–Triassic (P–Tr) section from the southern Sydney Basin. The PTME is identified by a negative shift in δ13Corg of ~ 3.8‰ occurring approximately …


Infrared Spectra Of Mass-Selected Al+_(Ch4)Nn=1-6clusters, B Poad, C Thompson, E Bieske May 2013

Infrared Spectra Of Mass-Selected Al+_(Ch4)Nn=1-6clusters, B Poad, C Thompson, E Bieske

Berwyck L. J. Poad

Infrared spectra are recorded for Al+–(CH4)n n = 1–6 clusters in the CH stretch region (2800–3100 cm−1). The spectra, which are obtained by monitoring photofragmentation in a tandem mass spectrometer, are dominated by a single, narrow band corresponding to the totally symmetric C–H stretching mode of the CH4 subunits (rendered infrared active through the interaction with the Al+ cation). This band shifts progressively to higher wavenumber as the clusters becomes larger, concomitant with a weakening of the intermolecular Al+⋯CH4 bonds. Supporting ab initio calculations for the n = …


Mixing Laser Spectroscopy And Mass Spectrometry- Infrared Spectra Of Metal Cation- Hydrogen Complexes, Vikoras Dryza, Berwyck Poad, Evan Bieske May 2013

Mixing Laser Spectroscopy And Mass Spectrometry- Infrared Spectra Of Metal Cation- Hydrogen Complexes, Vikoras Dryza, Berwyck Poad, Evan Bieske

Berwyck L. J. Poad

We describe recent experiments in which mass spectrometry and laser spectroscopy are combined to characterize Li(+)-H(2), Na(+)-H(2), B(+)-H(2), and Al(+)-H(2) complexes in the gas-phase. The infrared spectra, which feature full resolution of rotational sub-structure, are recorded by monitoring M(+) photo fragments as the infrared wavelength is scanned. The spectra deliver detailed information on the way in which a hydrogen molecule is attached to a metal cation including the intermolecular separation, the force constant for the intermolecular bond and the H-H stretching frequency. The complexes all possess T-shaped equilibrium geometries and display a clear correlation between the length and force constant …


Infrared Spectra Of Mass-Selected Mg+-H2 And Mg +-D2 Complexes, Viktoras Dryza, Berwyck L. Poad, Evan J. Bieske May 2013

Infrared Spectra Of Mass-Selected Mg+-H2 And Mg +-D2 Complexes, Viktoras Dryza, Berwyck L. Poad, Evan J. Bieske

Berwyck L. J. Poad

Rotationally resolved infrared spectra of Mg(+)-H(2) and Mg(+)-D(2) are recorded in the H-H (4025-4080 cm(-1)) and D-D (2895-2945 cm(-1)) stretch regions by monitoring Mg(+) photofragments. The nu(HH) and nu(DD) transitions of Mg(+)-H(2) and Mg(+)-D(2) are red-shifted by 106.2 +/- 1.5 and 76.0 +/- 0.1 cm(-1) respectively from the fundamental vibrational transitions of the free H(2) and D(2) molecules. The spectra are consistent with a T-shaped equilibrium structure in which the Mg(+) ion interacts with a slightly perturbed H(2) or D(2) molecule. From the spectroscopic constants, a vibrationally averaged intermolecular separation of 2.716 A (2.687 A) is deduced for the ground …


Uv Photodissociation Action Spectroscopy Of Haloanilinium Ions In A Linear Quadrupole Ion Trap Mass Spectrometer, Christopher S. Hansen, Benjamin B. Kirk, Stephen J. Blanksby, Richard A. J O'Hair, Adam J. Trevitt Apr 2013

Uv Photodissociation Action Spectroscopy Of Haloanilinium Ions In A Linear Quadrupole Ion Trap Mass Spectrometer, Christopher S. Hansen, Benjamin B. Kirk, Stephen J. Blanksby, Richard A. J O'Hair, Adam J. Trevitt

Faculty of Science, Medicine and Health - Papers: part A

UV-vis photodissociation action spectroscopy is becoming increasingly prevalent because of advances in, and commercial availability of, ion trapping technologies and tunable laser sources. This study outlines in detail an instrumental arrangement, combining a commercial ion-trap mass spectrometer and tunable nanosecond pulsed laser source, for performing fully automated photodissociation action spectroscopy on gas-phase ions. The components of the instrumentation are outlined, including the optical and electronic interfacing, in addition to the control software for automating the experiment and performing online analysis of the spectra. To demonstrate the utility of this ensemble, the photodissociation action spectra of 4-chloroanilinium, 4-bromoanilinium, and 4-iodoanilinium cations …


Optical Dating Of Quartz Sediments And Accelerator Mass Spectrometry 14c Dating Of Bone Gelatin And Moa Eggshell: A Comparison Of Age Estimates For Non-Archaeological Deposits In New Zealand, Richard Holdaway, Richard Roberts, Nancy Beavan-Athfield, Jon M Olley, Trevor Worthy Mar 2013

Optical Dating Of Quartz Sediments And Accelerator Mass Spectrometry 14c Dating Of Bone Gelatin And Moa Eggshell: A Comparison Of Age Estimates For Non-Archaeological Deposits In New Zealand, Richard Holdaway, Richard Roberts, Nancy Beavan-Athfield, Jon M Olley, Trevor Worthy

Richard G Roberts

No abstract provided.


Associations Between Body Mass Index And Musculoskeletal Pain And Related Symptoms In Different Body Regions Among Workers, Isabel Moreira-Silva, Rute Santos, Sandra Abreu, Jorge Mota Jan 2013

Associations Between Body Mass Index And Musculoskeletal Pain And Related Symptoms In Different Body Regions Among Workers, Isabel Moreira-Silva, Rute Santos, Sandra Abreu, Jorge Mota

Faculty of Social Sciences - Papers (Archive)

Obesity rates are high among employed adults and have shown a consistent increase over the past few decades. Musculoskeletal disorders related to work are a major cause of disability in working individuals. The objective of this study was to verify the associations between weight status and musculoskeletal pain and related symptoms in different body regions among workers. The sample comprised 203 factory workers. Anthropometric measures were assessed with standardized protocols and body mass index (BMI) was calculated. Participants were classified as nonoverweight (BMI ≤ 24.9 kg/m2) or overweight/obese (BMI ≥ 25 kg/m2). Musculoskeletal pain and related …


Determining The Geometry Of Mass-Flow Bins - Some Important Considerations, Peter Arnold Jan 2013

Determining The Geometry Of Mass-Flow Bins - Some Important Considerations, Peter Arnold

Faculty of Engineering and Information Sciences - Papers: Part A

It has taken some time to obtain general acceptance but in recent times, at least in Australia, competent designers of mass-flow bins use techniques based on the traditional concepts of Jenike to determine the appropriate geometry for mass-flow hoppers to handle bulk solids reliably. While the traditional Jenike design concepts may appear straightforward experience dictates that some important considerations need to be exercised during the design process, especially when handling the more difficult bulk solids, to ensure that the final bin construction performs to expectations. Some of the important considerations that this paper will highlight include: • Appropriate bulk solids …


Rapid Differentiation Of Isomeric Lipids By Photodissociation Mass Spectrometry Of Fatty Acid Derivatives, Huong T. Pham, Adam J. Trevitt, Todd W. Mitchell, Stephen J. Blanksby Jan 2013

Rapid Differentiation Of Isomeric Lipids By Photodissociation Mass Spectrometry Of Fatty Acid Derivatives, Huong T. Pham, Adam J. Trevitt, Todd W. Mitchell, Stephen J. Blanksby

Faculty of Science, Medicine and Health - Papers: part A

RATIONALE Both traditional electron ionization and electrospray ionization tandem mass spectrometry have demonstrated limitations in the unambiguous identification of fatty acids. In the former case, high electron energies lead to extensive dissociation of the radical cations from which little specific structural information can be obtained. In the latter, conventional collision-induced dissociation (CID) of even-electron ions provides little intra-chain fragmentation and thus few structural diagnostics. New approaches that harness the desirable features of both methods, namely radical-driven dissociation with discrete energy deposition, are thus required.

METHODS Herein we describe the derivatization of a structurally diverse suite of fatty acids as 4-iodobenzyl …


Product Branching Fractions Of The Ch + Propene Reaction From Synchrotron Photoionization Mass Spectrometry, Adam J. Trevitt, Matthew B. Prendergast, Fabien Goulay, John D. Savee, David L. Osborn, Craig A. Taatjes, Stephen R. Leone Jan 2013

Product Branching Fractions Of The Ch + Propene Reaction From Synchrotron Photoionization Mass Spectrometry, Adam J. Trevitt, Matthew B. Prendergast, Fabien Goulay, John D. Savee, David L. Osborn, Craig A. Taatjes, Stephen R. Leone

Faculty of Science, Medicine and Health - Papers: part A

The CH(X2Π) + propene reaction is studied in the gas phase at 298 K and 4 Torr (533.3 Pa) using VUV synchrotron photoionization mass spectrometry. The dominant product channel is the formation of C4H6 (m/z 54) + H. By fitting experimental photoionization spectra to measured spectra of known C4H6 isomers, the following relative branching fractions are obtained: 1,3-butadiene (0.63 ± 0.13), 1,2-butadiene (0.25 ± 0.05), and 1-butyne (0.12 ± 0.03) with no detectable contribution from 2-butyne. The CD + propene reaction is also studied and two product channels are observed that correspond to C4H6 (m/z 54) + D and C4H5D …


Surface Analysis Of Lipids By Mass Spectrometry: More Than Just Imaging, Shane R. Ellis, Simon H. Brown, Marc In Het Panhuis, Stephen J. Blanksby, Todd W. Mitchell Jan 2013

Surface Analysis Of Lipids By Mass Spectrometry: More Than Just Imaging, Shane R. Ellis, Simon H. Brown, Marc In Het Panhuis, Stephen J. Blanksby, Todd W. Mitchell

Faculty of Science, Medicine and Health - Papers: part A

Mass spectrometry is now an indispensable tool for lipid analysis and is arguably the driving force in the renaissance of lipid research. In its various forms, mass spectrometry is uniquely capable of resolving the extensive compositional and structural diversity of lipids in biological systems. Furthermore, it provides the ability to accurately quantify molecular-level changes in lipid populations associated with changes in metabolism and environment; bringing lipid science to the "omics" age. The recent explosion of mass spectrometry-based surface analysis techniques is fuelling further expansion of the lipidomics field. This is evidenced by the numerous papers published on the subject of …


Identification Of Distinct Body Mass Index Trajectories In Australian Children, C A. Magee, P Caputi, Donald C. Iverson Jan 2013

Identification Of Distinct Body Mass Index Trajectories In Australian Children, C A. Magee, P Caputi, Donald C. Iverson

Faculty of Social Sciences - Papers (Archive)

Background A limited number of studies have demonstrated that there may be distinct developmental trajectories of obesity during childhood. Objective To identify distinct trajectories of body mass index (BMI) in a large sample of Australian children. Methods Participants included 4601 children aged 45 years at baseline, who were followed up at ages 67 years, 89 years and 1011 years. Height and weight were measured at each of these time points, and used to calculate BMI. Growth Mixture Modelling was used to identify the presence of distinct BMI trajectories. Results Four distinct trajectories were identified (i) High Risk Overweight; (ii) Early …


The Longitudinal Relationship Between Sleep Duration And Body Mass Index In Children: A Growth Mixture Modeling Approach, Christopher A. Magee, Peter Caputi, Donald C. Iverson Jan 2013

The Longitudinal Relationship Between Sleep Duration And Body Mass Index In Children: A Growth Mixture Modeling Approach, Christopher A. Magee, Peter Caputi, Donald C. Iverson

Faculty of Social Sciences - Papers (Archive)

OBJECTIVE: A growing number of studies indicate that shorter sleep durations could contribute to obesity in children. The objective of this article was to further examine the longitudinal relationship between sleep duration and body mass index (BMI) in children by using a growth mixture modeling approach. METHOD: This article used prospective data from the Longitudinal Study of Australian Children. Participants included 1079 children aged 4 to 5 years (2004) followed up until age 10 to 11 years (2010). Growth mixture modeling was performed to examine the longitudinal association between sleep duration and body mass index within distinct body mass index …


Greenland Ice Sheet Mass Balance Reconstruction. Part I: Net Snow Accumulation (1600-2009), Jason E. Box, Noel Cressie, David H. Bromwich, Ji-Hoon Jung, Michiel Van Den Broeke, J H. Van Angelen, Richard R. Forster, Clement Miege, Ellen Mosley-Thompson, Bo Vinther, Joseph R. Mcconnell Jan 2013

Greenland Ice Sheet Mass Balance Reconstruction. Part I: Net Snow Accumulation (1600-2009), Jason E. Box, Noel Cressie, David H. Bromwich, Ji-Hoon Jung, Michiel Van Den Broeke, J H. Van Angelen, Richard R. Forster, Clement Miege, Ellen Mosley-Thompson, Bo Vinther, Joseph R. Mcconnell

Faculty of Engineering and Information Sciences - Papers: Part A

Ice core data are combined with RACMO2 regional climate model (RCM) output (1958-2010) to develop a reconstruction of the Greenland ice sheet net snow accumulation rate (Ât(G)) spanning years 1600-2009. Regression parameters from RCM output regressed on 86 ice cores are used with available cores in a given year resulting in the reconstructed values. Each core site’s residual variance is used to inversely weight the cores’ respective contributions. The interannual amplitude of the reconstructed accumulation rate is damped by the regressions and is thus calibrated to match that of the RCM data. Uncertainty and significance of changes is measured using …


A Personalized Hybrid Recommendation System Oriented To E-Commerce Mass Data In The Cloud, Fang Dong, Junzhou Luo, Xia Zhu, Yuxiang Wang, Jun Shen Jan 2013

A Personalized Hybrid Recommendation System Oriented To E-Commerce Mass Data In The Cloud, Fang Dong, Junzhou Luo, Xia Zhu, Yuxiang Wang, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Personalized recommendation technology in Ecommerce is widespread to solve the problem of product information overload. However, with the further growth of the number of E-commerce users and products, the original recommendation algorithms and systems will face several new challenges: (1) to model user’s interests more accurately; (2) to provide more diverse recommendation modes; and (3) to support large-scale expansion. To address these challenges, from the actual demands of E-commerce applications (as Made-in-China website), a personalized hybrid recommendation system, which can support massive data set, is designed and implemented in this paper by using Cloud technology. Hereinto, the recommendation algorithms are …


Automated Surface Sampling Of Lipids From Worn Contact Lenses Coupled With Tandem Mass Spectrometry, Simon H. Brown, Liam H. Huxtable, Mark D. P Willcox, Stephen J. Blanksby, Todd W. Mitchell Nov 2012

Automated Surface Sampling Of Lipids From Worn Contact Lenses Coupled With Tandem Mass Spectrometry, Simon H. Brown, Liam H. Huxtable, Mark D. P Willcox, Stephen J. Blanksby, Todd W. Mitchell

Faculty of Science, Medicine and Health - Papers: part A

The deposition of biological material (biofouling) onto polymeric contact lenses is thought to be a major contributor to lens discomfort and hence discontinuation of wear. We describe a method to characterize lipid deposits directly from worn contact lenses utilizing liquid extraction surface analysis coupled to tandem mass spectrometry (LESA-MS/MS). This technique effected facile and reproducible extraction of lipids from the contact lens surfaces and identified lipid molecular species representing all major classes present in human tear film. Our data show that LESA-MS/MS is a rapid and comprehensive technique for the characterization of lipid-related biofouling on polymer surfaces.


Increased Intake Of Dietary Polyunsaturated Fat Does Not Promote Whole Body Or Preferential Abdominal Fat Mass Loss In Overweight Adults, Sze-Yen Tan, Marijka Batterham, Linda Tapsell Nov 2012

Increased Intake Of Dietary Polyunsaturated Fat Does Not Promote Whole Body Or Preferential Abdominal Fat Mass Loss In Overweight Adults, Sze-Yen Tan, Marijka Batterham, Linda Tapsell

Dr Marijka Batterham

Objective: There is evidence that increasing the proportion of polyunsaturated fatty acids (PUFA) in a diet can enhance the rate of fat oxidation acutely. Higher PUFA in a diet has also been associated with greater abdominal fat loss in longer term studies. This study aimed to investigate if higher PUFA intake would result in greater fat mass loss over a 12-week period, mainly from the abdominal region. Methods: Data at the 12-week time point from two weight loss studies, both comparing high PUFA versus low PUFA diets was, accessed for 141 overweight subjects from the same area. Specifically, data on …


Performance Of Body Mass Index In Predicting Diabetes And Hypertension In The Eastern Province Of Saudi Arabia, Ali M. Almajwal, Nadira A. Al-Baghli, Marijka J. Batterham, Peter G. Williams, Khalid A. Al-Turki, Aqeel J. Al-Ghamdi Nov 2012

Performance Of Body Mass Index In Predicting Diabetes And Hypertension In The Eastern Province Of Saudi Arabia, Ali M. Almajwal, Nadira A. Al-Baghli, Marijka J. Batterham, Peter G. Williams, Khalid A. Al-Turki, Aqeel J. Al-Ghamdi

Dr Marijka Batterham

BACKGROUND AND OBJECTIVES: BMI is the most widely used measure to diagnose obesity but its accuracy and usefulness in Saudi subjects is unknown. This study aimed to assess the validity of standard BMI cut-point values in the Saudi population. SUBJECTS/ METHODS: 197,681 adults participated in a cross-sectional study to detect diabetes and hypertension in the Saudi Eastern province in 2004/5, with blood pressure, fasting blood sugar, height and weight measurements taken. Sensitivities, specificities, areas under the curves, predictive values, likelihood ratios, false positive, false negatives and total misclassification ratios were calculated for various BMI values determined from receiver operating characteristic …


Identification Of Phospholipids In Human Meibum By Nano-Electrospray Ionisation Tandem Mass Spectrometry, Jennifer T. Saville, Zhenjun Zhao, Mark Dp Willcox, Manjula A. Ariyavidana, Stephen J. Blanksby, Todd W. Mitchell Oct 2012

Identification Of Phospholipids In Human Meibum By Nano-Electrospray Ionisation Tandem Mass Spectrometry, Jennifer T. Saville, Zhenjun Zhao, Mark Dp Willcox, Manjula A. Ariyavidana, Stephen J. Blanksby, Todd W. Mitchell

Stephen Blanksby

Meibum is believed to be the major source of tear !lm lipids, which are vital in the prevention of excessevaporation of the aqueous phase. The complete lipid composition of meibum has yet to be established.While earlier studies reported the presence of phospholipids in human meibum, recent mass spectrometricstudies have not detected them. In this study we use electrospray ionisation tandem massspectrometry to investigate the presence of phospholipids in meibum and provide comparison to thephospholipid pro!le of tears.Lipids were extracted from human meibum and tear samples using standard biphasic methods andanalysed by nano-electrospray ionisation tandem mass spectrometry using targeted ion scans. …


Ozone Induced Dissociation: Elucidation Of Double Bond Position Within Mass-Selected Lipid Ions, Michael C. Thomas, Todd W. Mitchell, David G. Harman, Jane M. Deeley, Jessica R. Nealon, Stephen J. Blanksby Oct 2012

Ozone Induced Dissociation: Elucidation Of Double Bond Position Within Mass-Selected Lipid Ions, Michael C. Thomas, Todd W. Mitchell, David G. Harman, Jane M. Deeley, Jessica R. Nealon, Stephen J. Blanksby

Stephen Blanksby

Ions formed from lipids during electrospray ionization of crude lipid extracts have been mass-selected within a quadrupole linear ion trap mass spectrometer and allowed to react with ozone vapor. Gas-phase ion−molecule reactions between unsaturated lipid ions and ozone are found to yield two primary product ions for each carbon−carbon double bond within the molecule. The mass-to-charge ratios of these chemically induced fragments are diagnostic of the position of unsaturation within the precursor ion. This novel analytical technique, dubbed ozone-induced dissociation (OzID), can be applied both in series and in parallel with conventional collision-induced dissociation (CID) to provide near-complete structural assignment …


Direct Detection Of Additives And Degradation Products From Polymers By Liquid Extraction Surface Analysis Employing Chip-Based Nanospray Mass Spectrometry, Martin Paine, Phillip Barker, Shane A. Maclaughlin, Todd W. Mitchell, Stephen J. Blanksby Oct 2012

Direct Detection Of Additives And Degradation Products From Polymers By Liquid Extraction Surface Analysis Employing Chip-Based Nanospray Mass Spectrometry, Martin Paine, Phillip Barker, Shane A. Maclaughlin, Todd W. Mitchell, Stephen J. Blanksby

Stephen Blanksby

Rationale: Polymer-based surface coatings in outdoor applications experience accelerated degradation due to exposure to solar radiation, oxygen and atmospheric pollutants. These deleterious agents cause undesirable changes to the polymers aesthetic and mechanical properties reducing its lifetime. The use of antioxidants such as hindered amine light stabilisers (HALS) retard these degradative processes, however, mechanisms for HALS action and polymer degradation are poorly understood. Methods: Detection of the hindered amine light stabiliser (HALS) TINUVIN®123 (bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate) and the polymer degradation products directly from a polyester-based coil coating was achieved by liquid extraction surface analysis (LESA) coupled to a triple quadrupole QTRAP® …


Subunit Exchange Of Polydisperse Proteins: Mass Spectrometry Reveals Consequences Of Αa-Crystallin Truncation, J. Andrew Aquilina, Justin Benesch, Lin Lin Ding, Orna Yaron, Joseph Horwitz, Carol Robinson Oct 2012

Subunit Exchange Of Polydisperse Proteins: Mass Spectrometry Reveals Consequences Of Αa-Crystallin Truncation, J. Andrew Aquilina, Justin Benesch, Lin Lin Ding, Orna Yaron, Joseph Horwitz, Carol Robinson

J. A. Aquilina

The small heat shock protein, α-crystallin, plays a key role in maintaining lens transparency by chaperoning structurally compromised proteins. This is of particular importance in the human lens, where proteins are exposed to post-translational modifications over the life-time of an individual. Here, we examine the structural and functional consequences of one particular modification of αA-crystallin involving the truncation of 5 C-terminal residues (αA1–168). Using novel mass spectrometry approaches and established biophysical techniques, we show that αA1–168 forms oligomeric assemblies with a lower average molecular mass than wild-type αA-crystallin (αAWT). Also apparent from the mass spectra of both αAWT and αA1–168 …


Tandem Mass Spectrometry Reveals The Quaternary Organization Of Macromolecular Assemblies, J L Benesch, Andrew Aquilina, Brandon T. Ruotolo, Frank Sobott, C V Robinson Oct 2012

Tandem Mass Spectrometry Reveals The Quaternary Organization Of Macromolecular Assemblies, J L Benesch, Andrew Aquilina, Brandon T. Ruotolo, Frank Sobott, C V Robinson

J. A. Aquilina

The application of mass spectrometry (MS) to the study of progressively larger and more complex macromolecular assemblies is proving increasingly useful for structural biologists. The scope of this approach has recently been widened through the application of a tandem MS procedure. This two-step technique involves the selection of specific assemblies in the gas phase, and inducing their dissociation through collisions with argon atoms. Here we investigate the mechanism of this process and show that dissociation of subunits from a macromolecular assembly follows a sequential pathway, with the partitioning of charge between the dissociation products governed primarily by their relative surface …


Increased Intake Of Dietary Polyunsaturated Fat Does Not Promote Whole Body Or Preferential Abdominal Fat Mass Loss In Overweight Adults, Sze-Yen Tan, Marijka Batterham, Linda Tapsell Jul 2012

Increased Intake Of Dietary Polyunsaturated Fat Does Not Promote Whole Body Or Preferential Abdominal Fat Mass Loss In Overweight Adults, Sze-Yen Tan, Marijka Batterham, Linda Tapsell

L. C. Tapsell

Objective: There is evidence that increasing the proportion of polyunsaturated fatty acids (PUFA) in a diet can enhance the rate of fat oxidation acutely. Higher PUFA in a diet has also been associated with greater abdominal fat loss in longer term studies. This study aimed to investigate if higher PUFA intake would result in greater fat mass loss over a 12-week period, mainly from the abdominal region.

Methods: Data at the 12-week time point from two weight loss studies, both comparing high PUFA versus low PUFA diets was, accessed for 141 overweight subjects from the same area. Specifically, data on …


Paint Spray Mass Spectrometry For The Detection Of Additives From Polymers On Conducting Surfaces, Martin R.L Paine, Philip J. Barker, Stephen J. Blanksby Jan 2012

Paint Spray Mass Spectrometry For The Detection Of Additives From Polymers On Conducting Surfaces, Martin R.L Paine, Philip J. Barker, Stephen J. Blanksby

Faculty of Science, Medicine and Health - Papers: part A

Paint Spray is developed as a direct sampling ionisation method for mass spectrometric analysis of additives in polymer-based surface coatings. The technique simply involves applying an external high voltage (5 kV) to the wetted sample placed in front of the mass spectrometer inlet and represents a much simpler ionisation technique compared to those currently available. The capabilities of Paint Spray are demonstrated herein with the detection of four commercially available hindered amine light stabilisers; TINUVIN® 770, TINUVIN® 292, TINUVIN® 123 and TINUVIN® 152 directly from thermoset polyester-based coil coatings. Paint Spray requires no sample preparation or pre-treatment and combined with …


Direct Detection Of Additives And Degradation Products From Polymers By Liquid Extraction Surface Analysis Employing Chip-Based Nanospray Mass Spectrometry, Martin Paine, Phillip Barker, Shane A. Maclaughlin, Todd W. Mitchell, Stephen J. Blanksby Jan 2012

Direct Detection Of Additives And Degradation Products From Polymers By Liquid Extraction Surface Analysis Employing Chip-Based Nanospray Mass Spectrometry, Martin Paine, Phillip Barker, Shane A. Maclaughlin, Todd W. Mitchell, Stephen J. Blanksby

Faculty of Science - Papers (Archive)

Rationale: Polymer-based surface coatings in outdoor applications experience accelerated degradation due to exposure to solar radiation, oxygen and atmospheric pollutants. These deleterious agents cause undesirable changes to the polymers aesthetic and mechanical properties reducing its lifetime. The use of antioxidants such as hindered amine light stabilisers (HALS) retard these degradative processes, however, mechanisms for HALS action and polymer degradation are poorly understood. Methods: Detection of the hindered amine light stabiliser (HALS) TINUVIN®123 (bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate) and the polymer degradation products directly from a polyester-based coil coating was achieved by liquid extraction surface analysis (LESA) coupled to a triple quadrupole QTRAP® …


The Epididymal Soluble Prion Protein Forms A High-Molecular-Mass Complex In Association With Hydrophobic Proteins, Heath W. Ecroyd, Maya Belghazi, Jean-Louis Dacheux, Jean-Luc Gatti Dec 2011

The Epididymal Soluble Prion Protein Forms A High-Molecular-Mass Complex In Association With Hydrophobic Proteins, Heath W. Ecroyd, Maya Belghazi, Jean-Louis Dacheux, Jean-Luc Gatti

Heath Ecroyd

We have shown previously that a 'soluble' form of PrP (prion protein), not associated with membranous vesicles, exists in the male reproductive fluid [Ecroyd, Sarradin, Dacheux and Gatti (2004) Biol. Reprod. 71, 993-1001]. Attempts to purify this 'soluble' PrP indicated that it behaves like a high-molecular-mass complex of more than 350 kDa and always co-purified with the same set of proteins. The main associated proteins were sequenced by MS and were found to match to clusterin (apolipoprotein J), BPI (bacterial permeability-increasing protein), carboxylesterase-like urinary excreted protein (cauxin), beta-mannosidase and beta-galactosidase. Immunoblotting and enzymatic assay confirmed the presence of clusterin and …


Identification Of Abundant Alkyl Ether Glycerophospholipids In The Human Lens By Tandem Mass Spectrometry Techniques, Roger J. Truscott, Jane Deeley, Todd W. Mitchell, Michael Thomas, Stephen J. Blanksby Nov 2011

Identification Of Abundant Alkyl Ether Glycerophospholipids In The Human Lens By Tandem Mass Spectrometry Techniques, Roger J. Truscott, Jane Deeley, Todd W. Mitchell, Michael Thomas, Stephen J. Blanksby

Stephen Blanksby

Previous studies have shown that the human lens contains glycerophospholipids with ether linkages. These lipids differ from conventional glycerophospholipids in that the sn-1 substituent is attached to the glycerol backbone via an 1-O-alkyl or an 1-O-alk-1'-enyl ether rather than an ester bond. The present investigation employed a combination of collision-induced dissociation (CID) and ozone-induced dissociation (OzID) to unambiguously distinguish such 1-O-alkyl and 1-O-alk-1'-enyl ethers. Using these methodologies the human lens was found to contain several abundant 1-O-alkyl glycerophos-phoethanolamines, including GPEtn(16:0e/9Z-18:1), GPEtn(11Z-18:1e/9Z-18:1), and GPEtn(18:0e/9Z-18:1), as well as a related series of unusual 1-O-alkyl glycerophosphoserines, including GPSer(16:0e/9Z-18:1), GPSer(11Z-18:1e/9Z-18:1), GPSer(18:0e/9Z-18:1) that to our …


Increased Intake Of Dietary Polyunsaturated Fat Does Not Promote Whole Body Or Preferential Abdominal Fat Mass Loss In Overweight Adults, Sze-Yen Tan, Marijka Batterham, Linda Tapsell Jan 2011

Increased Intake Of Dietary Polyunsaturated Fat Does Not Promote Whole Body Or Preferential Abdominal Fat Mass Loss In Overweight Adults, Sze-Yen Tan, Marijka Batterham, Linda Tapsell

Faculty of Health and Behavioural Sciences - Papers (Archive)

Objective: There is evidence that increasing the proportion of polyunsaturated fatty acids (PUFA) in a diet can enhance the rate of fat oxidation acutely. Higher PUFA in a diet has also been associated with greater abdominal fat loss in longer term studies. This study aimed to investigate if higher PUFA intake would result in greater fat mass loss over a 12-week period, mainly from the abdominal region.

Methods: Data at the 12-week time point from two weight loss studies, both comparing high PUFA versus low PUFA diets was, accessed for 141 overweight subjects from the same area. Specifically, data on …