bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural characterization of product ions by electrospray ionization and quadrupole time‐of‐flight mass spectrometry to support regulatory analysis of veterinary drug residues in foods. Part 2: Benzimidazoles, nitromidazoles, phenothiazines, and mectins
Authors: Nuñez Alberto , Lehotay Steven J. , Geis‐Asteggiante Lucía 
Published: March 2015

RationaleAnalysis for identification and quantification of regulated veterinary drug residues in foods is usually achieved by liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS). The instrumental method requires the selection of characteristic ions, but structural elucidation is seldom performed to help ensure accuracy. This study is a continuation of previous work to characterize selected product ions in support of regulatory monitoring programs.MethodsThe tandem mass spectra of 28 veterinary drugs from a previously published LC/MS/MS method were acquired with a high‐resolution quadrupole time‐of‐flight (Q‐TOF) mass spectrometer using electrospray ionization (ESI) in positive mode. The TOF analyzer was calibrated to achieve a mass accuracy error <5 ppm for the MS and MS/MS modes, and samples were infused for data acquisition.ResultsThe high mass accuracy achieved in Q‐TOF allowed elucidation of the formulae of the product ions previously selected for qualitative identification. Rational interpretation of results was made and compared with the published literature, and the structure for the MS/MS product ions of four classes of regulated drugs (mectins, benzimidazoles, nitroimidazoles, and phenothiazines), totaling 28 compounds, were examined leading to the report of new structures or confirmation of published structures using low‐resolution MS.ConclusionsStructural characterization of the product ions selected for identification and quantification of veterinary drug residues is important information for regulatory monitoring programs in defense of regulatory enforcement actions. This study has allowed structural elucidation of 84 MS/MS product ions previously selected for the LC/MS/MS analysis of 28 drug analytes. Published in 2015. This article is a U.S. Government work and is in the public domain in the USA.
Mass spectrometric identification of the N‐monosubstituted N‐hydroxylamino functionality in protonated analytes via ion/molecule reactions in tandem mass spectrometry
Authors: Sheng Huaming , Tang Weijuan , Yerabolu Ravikiran , Kong John Y. , Williams Peggy E. , Zhang Minli , Kenttämaa Hilkka I. 
Published: March 2015

RationaleN‐Monosubstituted hydroxylamines correspond to an important class of metabolites for many bioactive molecules. In this study, a tandem mass spectrometric method based on ion/molecule reactions was developed for the identification of compounds with the N‐monosubstituted hydroxylamino functionality.MethodsThe diagnostic ion/molecule reaction occurs between protonated analytes with 2‐methoxypropene (MOP) inside a linear quadrupole ion trap mass spectrometer.ResultsMost protonated compounds with N‐monosubstituted and disubstituted hydroxylamino and oxime functional groups react with MOP via proton transfer and formation of a stable adduct in a linear quadrupole ion trap mass spectrometer. However, only protonated compounds with N‐monosubstituted hydroxylamino groups form the characteristic MOP adduct–MeOH product. Possible mechanisms of this reaction are discussed.ConclusionsA method based on functional group‐selective ion/molecule reactions in a linear quadrupole ion trap mass spectrometer has been demonstrated to allow the identification of protonated compounds with the N‐monosubstituted hydroxylamino functionality. Only N‐monosubstituted hydroxylamines react with MOP via formation of an adduct that has eliminated methanol. Copyright © 2015 John Wiley & Sons, Ltd.
Exploring the complexity of oil sands process‐affected water by high efficiency supercritical fluid chromatography/orbitrap mass spectrometry
Authors: Pereira A. S. , Martin J. W. 
Published: March 2015

RationaleApproximately 1 billion m3 of oil sands process‐affected water (OSPW) is currently stored in tailings ponds in Northern Alberta, Canada. The dissolved organic compounds in OSPW have been termed a supercomplex mixture of bitumen‐derived substances and continuing efforts to understand its underlying chemical composition are important for evaluating its environmental hazards.MethodsPacked column supercritical fluid chromatography (SFC) was applied to OSPW analysis for the first time. By combining four columns in series (each 25 cm × 4.6 mm I.D., 5.0 µm bare silica) approximately 80,000 plates were achieved on a 1 m column. Using a simple fixed restrictor, the SFC eluent was coupled directly to ultrahigh‐resolution orbitrap mass spectrometry (SFC/Orbitrap‐MS).ResultsSFC/Orbitrap‐MS, with positive and negative atmospheric pressure chemical ionization (APCI +/–), revealed the partial or full chromatographic separation of isomers for a wide array of chemical species, including naphthenic acids (CnH2n + ZO2) and unknown sulfur‐ and nitrogen‐containing molecules. For smaller compounds (e.g. naphthenic acids where n ≤10), or for larger structurally constrained compounds (e.g. C16 naphthenic acid with 9 double‐bond equivalents), apparent baseline resolution of many isomers was possible. Isomer‐specific MS/MS experiments furthermore allowed characterization of functional groups in novel species. For example, in APCI+ mode, up to 16 isomers of C6H11ON were revealed to have amide and amino functionalities.ConclusionsThis combination of high efficiency chromatography and ultra‐high mass resolution detection resulted in a powerful method with capabilities for characterizing or 'fingerprinting' unknown species with little interference. The method has great promise for environmental monitoring and forensics in the oil sands region, as well as for further studies on the composition of dissolved organic compounds in OSPW. Copyright © 2015 John Wiley & Sons, Ltd.
Acquisition of the depth profiles and reproducible mass spectra in matrix‐assisted laser desorption/ionization of inhomogeneous samples
Authors: Ahn Sung Hee , Park Kyung Man , Moon Jeong Hee , Lee Seong Hoon , Kim Myung Soo 
Published: March 2015

RationaleIn our previous analysis of the matrix‐assisted laser desorption/ionization (MALDI) spectra of peptides, we treated their depth profiles in solid samples as homogeneous. Here, we wanted to determine if the reproducible MALDI spectra and linear calibration curves reported previously would be obtained even when the depth profiles were inhomogeneous.MethodsWe derived a formula relating shot‐number‐dependent ion abundance data in temperature‐controlled MALDI with the analyte depth profile in a solid sample. We prepared samples containing peptides, amino acids, and serotonin in α‐cyano‐4‐hydroxycinnamic acid matrix by vacuum‐drying and micro‐spotting methods, recorded their MALDI spectra, and analyzed them with the aforementioned formula.ResultsFor the samples prepared by vacuum‐drying, the analyte depth profiles were inhomogeneous and maximized at the sample surface. Although the MALDI spectra changed as the shot continued, their sum over the entire set of spectra acquired from a spot was reproducible. Similarly, a high‐quality calibration curve could be obtained with the spectral data summed over the entire set. Depth profiles were homogeneous for samples prepared by micro‐spotting.ConclusionsA method has been developed to obtain a reproducible MALDI spectrum and a linear calibration curve for an analyte with an inhomogeneous depth profile in a solid sample. Copyright © 2015 John Wiley & Sons, Ltd.
Stable isotope analysis of Dacryoconarid carbonate microfossils: a new tool for Devonian oxygen and carbon isotope stratigraphy
Authors: Frappier Amy Benoit , Lindemann Richard H. , Frappier Brian R. 
Published: March 2015

RationaleDacryoconarids are extinct marine zooplankton known from abundant, globally distributed calcite microfossils in the Devonian, but their shell stable isotope composition has not been previously explored. Devonian stable isotope stratigraphy is currently limited to less common invertebrates or bulk rock analyses of uncertain provenance. As with Cenozoic planktonic foraminifera, isotopic analysis of dacryoconarid shells could facilitate higher‐resolution, geographically widespread stable isotope records of paleoenvironmental change, including marine hypoxia events, climate changes, and biocrises. We explored the use of Dacryoconarid isotope stratigraphy as a viable method in interpreting paleoenvironments.MethodsWe applied an established method for determining stable isotope ratios (δ13C, δ18O values) of small carbonate microfossils to very well‐preserved dacryoconarid shells. We analyzed individual calcite shells representing five common genera using a Kiel carbonate device coupled to a MAT 253 isotope ratio mass spectrometer. Calcite shell δ13C and δ18O values were compared by taxonomic group, rock unit, and locality.ResultsSingle dacryoconarid calcite shells are suitable for stable isotope analysis using a Kiel‐IRMS setup. The dacryoconarid shell δ13C values (–4.7 to 2.3‰) and δ18O values (–10.3 to –4.8‰) were consistent across taxa, independent of shell size or part, but varied systematically through time. Lower fossil δ18O values were associated with warmer water temperature and more variable δ13C values were associated with major bioevents. Dacryoconarid δ13C and δ18O values differed from bulk rock carbonate values.ConclusionsDacryoconarid individual microfossil δ13C and δ18O values are highly sensitive to paleoenvironmental changes, thus providing a promising avenue for stable isotope chemostratigraphy to better resolve regional to global paleoceanographic changes throughout the upper Silurian to the upper Devonian. Our results warrant further exploration of dacryoconarid stable isotope proxy sensitivity, the isotopic contrast among dacryoconarids, other taxa, and bulk rock, as well as other potential dacryoconarid proxies (Mg/Ca, Sr/Ca, 87Sr/86Sr, microlaser and ion microprobe isotope techniques, and clumped isotopes) for stratigraphic research. Copyright © 2015 John Wiley & Sons, Ltd.
Cryogenic separation of an oxygen–argon mixture in natural air samples for the determination of isotope and molecular ratios
Authors: Keedakkadan Habeeb Rahman , Abe Osamu 
Published: March 2015

RationaleThe separation and purification of oxygen–argon mixtures are critical in the high‐precision analysis of Δ17O and δ(O2/Ar) for geochemical applications. At present, chromatographic methods are used for the separation and purification of oxygen–argon mixtures or pure oxygen, but these methods require the use of high‐purity helium as a carrier gas. Considerable interest has been expressed in the development of a helium‐free cryogenic separation of oxygen–argon mixtures in natural air samples.MethodsThe precise and simplified cryogenic separation of oxygen–argon mixtures from natural air samples presented here was made possible using a single 5A (30/60 mesh) molecular sieve column. The method involves the trapping of eluted gases using molecular sieves at liquid nitrogen temperature, which is associated with isotopic fractionation. We tested the proposed method for the determination of isotopic fractionations during the gas exchange between water and atmospheric air at equilibrium. The dependency of fractionation was studied at different water temperatures and for different methods of equilibration (bubbling and stirring). Isotopic and molecular fractionations during gas desorption from molecular sieves were studied for different amounts and types of molecular sieves.ResultsRepeated measurements of atmospheric air yielded a reproducibility (±SD) of 0.021 ‰, 0.044 ‰, 15 per meg and 1.9 ‰ for δ17O, δ18O, Δ17O and δ(O2/Ar) values, respectively. We applied the method to determine equilibrium isotope fractionation during gas exchange between air and water. Consistent δ18O and Δ17O results were obtained with the latest two studies, whereas there was a significant difference in δ18O values between seawater and deionized water.ConclusionsWe have revised a helium‐free, cryogenic separation of oxygen–argon mixtures in natural air samples for isotopic and molecular ratio analysis. The use of a single 13X (1/8" pellet) molecular sieve yielded the smallest isotopic and molecular fractionations, and this fractionation by molecular sieves can be corrected by the amount of molecular sieve used in the experiment. The reproducibility of the method was tested by the measurement of the oxygen isotope ratios of dissolved oxygen at equilibrium with atmospheric air. We confirmed that the choice of methods for making air‐equilibrated water was not related to the magnitude of isotope fractionation, whereas there was a difference between seawater and deionized water. Copyright © 2015 John Wiley & Sons, Ltd.
Phase I trial of volasertib, a Polo-like kinase inhibitor, plus platinum agents in solid tumors: safety, pharmacokinetics and activity
Authors: Awada Ahmad , Dumez Herlinde , Aftimos Philippe G. , Costermans Jo , Bartholomeus Sylvie , Forceville Kathleen , Berghmans Thierry , Meeus Marie-Anne , Cescutti Jessica , Munzert Gerd , Pilz Korinna , Liu Dan , Schöffski Patrick 
Published: March 2015

SummaryBackground This trial evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics, and activity of volasertib, a selective Polo-like kinase 1 inhibitor that induces mitotic arrest and apoptosis, combined with cisplatin or carboplatin in patients with advanced/metastatic solid tumors (NCT00969761; 1230.6). Methods Sequential patient cohorts (3 + 3 dose-escalation design) received a single infusion of volasertib (100–350 mg) with cisplatin (60–100 mg/m2) or carboplatin (area under the concentration versus time curve [AUC]4–AUC6) on day 1 every 3 weeks for up to six cycles. Sixty-one patients received volasertib/cisplatin (n = 30) or volasertib/carboplatin (n = 31) for a median of 3.5 (range, 1–6) and 2.0 (range, 1–6) treatment cycles, respectively. Results The most common cycle 1 dose-limiting toxicities (DLTs) were thrombocytopenia, neutropenia and fatigue. MTDs (based on cycle 1 DLTs) were determined to be volasertib 300 mg plus cisplatin 100 mg/m2 and volasertib 300 mg plus carboplatin AUC6. Co-administration did not affect the pharmacokinetics of each drug. Partial responses were observed in two patients in each arm. Stable disease was achieved in 11 and six patients treated with volasertib/cisplatin and volasertib/carboplatin, respectively. Conclusions Volasertib plus cisplatin or carboplatin at full single-agent doses was generally manageable and demonstrated activity in heavily pretreated patients with advanced solid tumors.
Effect of Different Deacidification Methods on Phytonutrients Retention in Deacidified Fractionated Palm Oil
Authors: Kumar P. K. Prasanth , Krishna A. G. Gopala 
Published: March 2015

AbstractCrude red palm oil of 11.4 % free fatty acid content was dry fractionated to obtain liquid crude red palm olein which was deacidified using enzyme (lipase from Rhizomucor miehei), solvent (ethanol), and chemical (aqueous sodium hydroxide), and its effect on physicochemical characteristics and phytonutrients retention was evaluated. Enzymatic deacidification showed 100 % product yield and no neutral lipid loss, whereas yields of 78 and 62 % and neutral lipid loss of 12 and 30 % were observed for solvent and chemical deacidification, respectively. Variation in viscosity (25.3–37.2 cSt at 40 °C), slip melting point (15–36 °C), monoacylglycerols (1.7–3.3 %), and diacylglycerols (5.8–27.9 %) were also observed. Carotenoid content was slightly reduced by enzymatic (535 mg/kg), solvent (556 mg/kg), and chemical (526 mg/kg) deacidification. Retention of phytonutrients such as phytosterols (1,235 mg/kg), total tocopherols (965 mg/kg), squalene (301 mg/kg), coenzyme Q10 (25.9 mg/kg), and total phenolics (3 mg/kg) was highest following enzymatic deacidification. The IC50 value of the enzymatic deacidified sample (21.8 mg/ml) indicates more radical scavenging activity than in samples obtained using solvent (42.0 mg/ml) and chemical (28.8 mg/ml) methods.
Quantitative Determination of Natural Glycolipids from Oil Seed by Automated High‐Performance Thin‐Layer Chromatography (HPTLC)
Authors: Wenzel O. , Fernández J. , Sohling U. , Niemeyer B. 
Published: March 2015

AbstractThe role of glycolipids in vegetable oil refining and production of bio‐based fuels has not been disclosed so far. Such investigations required a reliable and reproducible quantitative determination of these compounds. Fundamental data were therefore established on the quantitative determination of glycolipids in vegetable oil gums by means of high‐performance thin‐layer chromatography (HPTLC). Concentrating on five abundant natural glycolipid classes found in these oils, identification of a suitable separation method for the employed glycolipid mixture and those parameters relevant for successful detection were considered in detail. The special importance of sample volume when employing quantitative HPTLC was discussed. Acetone/chloroform/water 6:3:0.4 (v/v/v) was identified as a convenient mobile phase for the investigated issue. A derivatization reagent comprising methanol, copper(II)sulfate pentahydrate, sulfuric acid 98 %, and phosphoric acid 85 % was identified. Subsequent heating at 135 °C for 10 min finished the derivatization and enabled detection at λ = 370 nm. Calibration curves ranging from 1500 to 31.25 ng/mL, regarding both peak area and peak height, were determined. The good correlation of parameters enabled the application of the method to real oil gum samples from sunflower and soybean oil. This revealed that digalactosyldiglycerides in combination with either sterylglucosides or acylated sterylglucosides represented the major glycolipid classes in these oils.
Different risk factors between reflux symptoms and mucosal injury in gastroesophageal reflux disease
Authors: Li Chung‐Hsien , Hsieh Tsung‐Cheng , Hsiao Tsung‐Hsien , Wang Pin‐Chao , Tseng Tai‐Chung , Lin Hans Hsienhong , Wang Chia‐Chi 
Published: March 2015

AbstractGastroesophageal reflux disease (GERD) is diagnosed based on typical symptoms in clinical practice. It can be divided into two groups using endoscopy: erosive and nonerosive reflux disease (NERD). This study aims to determine the risk factors of reflux symptoms and mucosal injury. This was a two‐step case‐control study derived from a cohort of 998 individuals having the data of reflux disease questionnaire (RDQ) and endoscopic findings. Those with minor reflux symptoms were excluded. The first step compared symptomatic GERD patients with healthy controls. The 2nd step compared patients with erosive esophagitis with healthy controls. In this study, the prevalence of symptomatic GERD and erosive esophagitis were 163 (16.3%) and 166 (16.6%), respectively. A total of 507 asymptomatic individuals without mucosal injury of the esophagus on endoscopy were selected as healthy controls. Compared with healthy controls, multivariate analyses showed that symptomatic GERD patients had a higher prevalence of hypertriglyceridemia [odds ratio (OR), 1.83; 95% confidence interval (CI) 1.13–2.96] and obesity (OR, 1.85; 95% CI 1.08–3.02). By contrast, male sex (OR, 2.24; 95% CI 1.42–3.52), positive Campylo‐like organism (CLO) test (OR, 0.56; 95% CI 0.37–0.84), and hiatus hernia (OR, 14.36; 95% CI 3.05–67.6) were associated with erosive esophagitis. In conclusion, obesity and hypertriglyceridemia were associated with reflux symptoms. By contrast, male sex, negative infection of Helicobacter pylori, and hiatus hernia were associated with mucosal injury. Our results suggested that risk factors of reflux symptoms or mucosal injury might be different in GERD patients. The underlying mechanism awaits further studies to clarify.
Rehabilitation Management of Hemicorporectomy
Authors: Cavalheiro Daniela Potas , Marten Teixeira João Eduardo , Braga Douglas Martins , Pessoa Claudia Vöhringer , Ceregatti Marina , McNeill Ingham Sheila Jean 
Published: March 2015

AbstractThis is a case report of a 55‐year‐old woman who was treated with a hemicorporectomy consequent to an invasive undifferentiated sacral chordoma. We describe the clinical course and rehabilitation process in an amputee outpatient clinic and report outcome measures such as the modified Functional Reach Test, the Amputee Mobility Predictor, the Functional Independence Measure, and the Short‐Form Health Survey after 9 months of rehabilitation.
Functional Coupling of TRPV4, IK, and SK Channels Contributes to Ca2+‐Dependent Endothelial Injury in Rodent Lung
Authors: Lin Mike T. , Jian Ming‐Yuan , Taylor Mark S. , Cioffi Donna L. , Yap Fui C. , Liedtke Wolfgang , Townsley Mary I. 
Published: March 2015

Our previous work has shown that the increased lung endothelial permeability response to 14,15‐epoxyeicosatrienoic acid (14,15‐EET) in rat lung requires Ca2+ entry via vanilloid type‐4 transient receptor potential (TRPV4) channels. Recent studies suggest that activation of TRPV4 channels in systemic vascular endothelium prolongs agonist‐induced hyperpolarization and amplifies Ca2+ entry by activating Ca2+‐activated K+ (KCa) channels, resulting in vessel relaxation. Activation of endothelial KCa channels thus has potential to increase the electrochemical driving force for Ca2+ influx via TRPV4 channels and to amplify permeability responses to TRPV4 activation in lung. To examine this hypothesis, we used Western blot analysis, electrophysiological recordings, and isolated‐lung permeability measurements to document expression of TRPV4 and KCa channels and the potential for functional coupling. The results show that rat pulmonary microvascular endothelial cells express TRPV4 and 3 KCa channels of different conductances: large (BK), intermediate (IK), and small (SK3). However, TRPV4 channel activity modulates the IK and SK3, but not the BK, channel current density. Furthermore, the TRPV4‐mediated permeability response to 14,15‐EET in mouse lung is significantly attenuated by pharmacologic blockade of IK and SK3, but not BK, channels. Collectively, this functional coupling suggests that endothelial TRPV4 channels in rodent lung likely form signaling microdomains with IK and SK3 channels and that the integrated response dictates the extent of lung endothelial injury caused by 14,15‐EET.
‘Total cost of ownership’ of scholarly communication: managing subscription and APC payments together
Authors: LAWSON Stuart 
Published: March 2015

ABSTRACTManaging subscription journals and open access charges together has created challenges which may in part be dealt with by offsetting the two revenue streams against each other. In order to do this, it is necessary to have reliable financial data about the extent of the two interacting markets. Jisc Collections has been undertaking data collection regarding universities' article publication charge (APC) expenditure. This process is difficult without a standardized way of recording data, so Jisc Collections has developed a standard data collection template and is helping institutions to release data openly. If available data become more comprehensive and transparent, then all parties (libraries, publishers, research funders, and intermediaries) will have better knowledge of the APC market and can more accurately predict the effects of offsetting.