38 research outputs found

    A collision cross section database for extractables and leachables from food contact materials

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    The chemicals in food contact materials (FCMs) can migrate into food and endanger human health. In this study, we developed a database of traveling wave collision cross section in nitrogen ((CCSN2)-C-TW) values for extractables and leachables from FCMs. The database contains a total of 1038 (CCSN2)-C-TW values from 675 standards including those commonly used additives and nonintentionally added substances in FCMs. The (CCSN2)-C-TW values in the database were compared to previously published values, and 85.7, 87.7, and 64.9% M + H](+), M + Na](+), and M - H](-) adducts showed deviations <2%, with the presence of protomers, post-ion mobility spectrometry dissociation of noncovalent clusters and inconsistent calibration are possible sources of CCS deviations. Our experimental (CCSN2)-C-TW values were also compared to CCS values from three prediction tools. Of the three, CCSondemand gave the most accurate predictions. The (CCSN2)-C-TW database developed will aid the identification and differentiation of chemicals from FCMs in targeted and untargeted analysis

    The migration of NIAS from ethylene-vinyl acetate corks and their identification using gas chromatography mass spectrometry and liquid chromatography ion mobility quadrupole time-of-flight mass spectrometry

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    An exhaustive migration study of eight corks, made of ethylene–vinyl acetate, was carried out to identify any non-volatile and volatile compounds using an untargeted approach. The challenge associated with the structural elucidation of unknowns was undertaken using both ultra-high-performance liquid chromatography coupled to an ion-mobility separation quadrupole-time of flight mass spectrometer and gas chromatography mass spectrometry. A total of fifty compounds were observed to migrate from the corks, and among these additives such as antioxidants (Butyl 4-hydroxybenzoate, Irganox 1010, Irganox 1075, Irgafos 168 and BHT) or lubricants (EBO and octadecanamide, N,N'-1,2-ethanediylbis-) were identified. A high proportion (84%) of the detected compounds was non-intentionally added substances (NIAS), and included several cyclic oligomers with different chain sequences. NIAS, such as 2,6-bis(1,1-dimethylethyl)-4-ethyl and 7,9-ditert-butyl-1-oxaspiro[4.5]deca-6,9-diene-2,8-dione, break-down products, including hexa-, hepta- and nonadecanamide, N,N'-1,2-ethanediylbis-, and oxidation products were also identified. One cork was found to be unsuitable for use as a food contact material

    Prediction of Collision Cross-Section Values for Extractables and Leachables from Plastic Products

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    The use of ion mobility separation (IMS) in conjunction with high-resolution mass spectrometry has proved to be a reliable and useful technique for the characterization of small molecules from plastic products. Collision cross-section (CCS) values derived from IMS can be used as a structural descriptor to aid compound identification. One limitation of the application of IMS to the identification of chemicals from plastics is the lack of published empirical CCS values. As such, machine learning techniques can provide an alternative approach by generating predicted CCS values. Herein, experimental CCS values for over a thousand chemicals associated with plastics were collected from the literature and used to develop an accurate CCS prediction model for extractables and leachables from plastic products. The effect of different molecular descriptors and machine learning algorithms on the model performance were assessed. A support vector machine (SVM) model, based on Chemistry Development Kit (CDK) descriptors, provided the most accurate prediction with 93.3% of CCS values for M + H](+) adducts and 95.0% of CCS values for M + Na](+) adducts in testing sets predicted with <5% error. Median relative errors for the CCS values of the M + H](+) and M + Na](+) adducts were 1.42 and 1.76%, respectively. Subsequently, CCS values for the compounds in the Chemicals associated with Plastic Packaging Database and the Food Contact Chemicals Database were predicted using the SVM model developed herein. These values were integrated in our structural elucidation workflow and applied to the identification of plastic-related chemicals in river water. False positives were reduced, and the identification confidence level was improved by the incorporation of predicted CCS values in the suspect screening workflow

    Ultra-high performance liquid chromatography coupled to ion mobility quadrupole time-of-flight mass spectrometry for the identification of non-volatile compounds migrating from ´natural´ dishes

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    Although most new biomaterials for food industry applications are labelled ‘100% natural fabrication’ and ‘chemical-free’, certain compounds may migrate from those materials to the food, compromis- ing the organoleptic characteristics and safety of the product. In this work, the degree of compound migration from dishes made with four different biomaterials: bamboo, palm leaf, wood and wheat pulp was investigated. Migration tests were carried out using three food simulants, 10% ethanol (sim- ulant A), 3% acetic acid (simulant B), and 95% ethanol (simulant D2). Unequivocal identification of non-intentionally added substances (NIAS) is challenging even when using high-resolution mass spectrometry techniques however, a total of 25 different non-volatile compounds from the migration tests were identified and quantified using Ultra-high performance liquid chromatography coupled to ion mobility quadrupole time-of-flight mass spectrometry (UPLC-IMS-MS). In the bamboo samples three oligomers, cyclic diethylene glycol adipate, 3,6,9,16,19,22-hexaoxabicyclo[22.3.1]-octacosa-1(28),24,26- triene-2,10,15,23-tetrone and 1,4,7,14,17,20-hexaoxacyclohexacosane-8,13,21,26-tetrone exceeded the specified limits of migration

    Social cognition and executive functioning predictors of supervisors’ appraisal of interpersonal behaviour in the workplace following acquired brain injury

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    BACKGROUND: Social cognition and executive functioning difficulties following acquired brain injury have been linked to negative employment outcomes, such as demotion and loss of vocational roles. These are very counter-intuitive and challenging difficulties for other employees and work supervisors who have little or no brain injury knowledge, whose perceptions of play a key role in their responses to these difficulties and the final outcome of such problems for vocational status. OBJECTIVES: This study aimed to study the relationship between social cognition and executive functioning difficulties and the perceptions of work supervisors’ appraisal of survivor interpersonal behaviour and social skills in the workplace. METHOD: The performance of 73 survivors of acquired brain injury (47% TBI, 38% CVA, 15% other ABI type; 73% male; mean age 45.44 years, range 19-64 years; mean time since injury 6.36 years, range 10.5-31.33 years), currently in a vocational rehabilitation placement) on neuropsychological tests of executive functioning and social cognition was measured. Informant ratings on the Social Skills Factor subscale from the Work Personality Profile (WPP, Bolton&Roessler, 1986) were used as the primary outcome measure, a vocational functioning questionnaire assessing social and presentational aspects of workplace behaviour. The raters were non-clinical workplace informants acting in a supervisory role (supervisory placement providers and job coaches). RESULTS: Correlational analysis identified significant associations between the WPP and survivor goal-orientated planning and implementation, mentalising ability, recognition of positive and negative emotions, and recognition of simple sarcasm (all significant at p < 0.05). These correlates were entered into a stepwise multiple regression. The combination final of survivor mentalising ability and executive functioning explained 32%of the variance in the WPP ratings (F (2, 52) = 12.15, p < 0.001). CONCLUSION: Certain limitations of the study withstanding, the current findings add to previous literature in highlighting the relevance of survivor executive functioning and social cognition difficulties for the perceptions and appraisal of work colleagues, consistent with other studies that have identified negative vocational outcomes associated with such neuropsychological difficulties. The implications for vocational rehabilitation are discussed

    Improving Target and Suspect Screening High-Resolution Mass Spectrometry Workflows in Environmental Analysis by Ion Mobility Separation

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    Currently, the most powerful approach to monitor organic micropollutants (OMPs) in environmental samples is the combination of target, suspect, and nontarget screening strategies using high-resolution mass spectrometry (HRMS). However, the high complexity of sample matrices and the huge number of OMPs potentially present in samples at low concentrations pose an analytical challenge. Ion mobility separation (IMS) combined with HRMS instruments (IMS−HRMS) introduces an additional analytical dimension, providing extra information, which facilitates the identification of OMPs. The collision cross-section (CCS) value provided by IMS is unaffected by the matrix or chromatographic separation. Consequently, the creation of CCS databases and the inclusion of ion mobility within identification criteria are of high interest for an enhanced and robust screening strategy. In this work, a CCS library for IMS−HRMS, which is online and freely available, was developed for 556 OMPs in both positive and negative ionization modes using electrospray ionization. The inclusion of ion mobility data in widely adopted confidence levels for identification in environmental reporting is discussed. Illustrative examples of OMPs found in environmental samples are presented to highlight the potential of IMS−HRMS and to demonstrate the additional value of CCS data in various screening strategies

    Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

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    Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme

    Enhancement of the drainage of non-Newtonian liquid films by oscillation

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    SIGLEAvailable from British Library Document Supply Centre- DSC:DX175587 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    The Sisters of Charity of St. Vincent de Paul

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