352 research outputs found

    Semi-automated quantification of methylmalonic acid in human serum by LC-MS/MS

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    Background. Methylmalonic acid (MMA), a sensitive biomarker of functional vitamin B12 deficiency, is commonly determined by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using manual extraction and derivatization of MMA to reduce polarity prior to separation. Methods. In the present study we introduce a semi-automated extraction on a strong anion exchanger, HPLC separation on a BEH-amide column to separate serum MMA from its abundant isoform, succinic acid, followed by MS/MS detection and quantification. Results. The extraction of MMA plus internal standard provides full recovery and the method is linear between 0.03 mu mol/L and 20.0 mu mol/L (r(2) = 1.0) with intra-and inter-assay imprecision of 2.2%. Agreement with other laboratories has been demonstrated in external proficiency testing. Compared to both conventional GC-MS and LC-MS/MS methods, the correlation is r(2) > 0.99. Conclusions. The use of robotic pipetting, elimination of derivatization and improved separation by the BEH-amide column combined with HILIC chromatographic conditions significantly improve sample throughput compared to conventional methods. Using a single pipetting robot and LC-MS/MS instrument, this method is currently performing 180 analyses per day from 10 regional hospitals and several additional distant sites

    Relative impacts of the invasive Pacific oyster, Crassostrea gigas, over the native blue mussel, Mytilus edulis, are mediated by flow velocity and food concentration

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    The ecological impacts of invasive species can be severe, but are generally viewed as highly unpredictable. Recent methods combining per capita feeding rates, population abundances and environmental contexts have shown great utility in predicting invader impacts. Here, clearance rates of the invasive Pacific oyster, Crassostrea gigas, and native mussel, Mytilus edulis, were investigated in a laboratory experiment where oscillatory water flow and algal food concentrations were manipulated. Invasive oysters had lower clearance rates than native mussels in all experimental groups and did not differ among flow velocities or food concentrations. Native mussel clearance rates were higher at 5 cm s-1 compared to 0 and 15 cm s-1 flow velocities and increased with increasing food concentration. The Relative Impact Potential (RIP) metric was used to assess (i) the influence of flow velocity and food concentration on potential impacts of C. gigas on plankton resources and, (ii) the impacts of coexisting reefs, containing both species, on resources compared to monospecific native mussel beds. Greatest Relative Impact Potential of invasive oysters was seen at the lowest flow velocity, but became reduced with increasing flow velocity and food concentration. Relative Impact Potentials of coexisting reefs were generally greater than monospecific native mussel beds, with greatest impacts predicted at lowest flow velocity. We suggest that the greatest ecological impacts and competition potential of C. gigas will occur in areas with low flow velocity, but that increased flow will mediate co-existence between the two species

    The Ursinus Weekly, March 13, 1950

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    Seniors plan show, Back in civvies, as novel enterprise • Two profs to debate economic aid policy • Twenty fall victim to rushing tactics in spring campaign • Compton wins first at inter-collegiates; remains unbeaten • Y prexy to open Fun nite agenda with camping slides • Committee finishes proposed revisions of soph rules plan • Greeks to entertain at party for frosh • Senator emphasizes new fiscal system • Pink and black set suave \u27Velvet mood\u27 • Faculty honors Morrison at anniversary celebration • Drives elicit small student response • Hilarious atmosphere pervades old T-G with Muench and minstrel high jinks • Dunc totes hockey stick from Devon to Dutchland • Dinelli\u27s The Man • Lecturing prof studies grass roots • Library constantly increases reserves of fiction and non-fiction volumes • May pageants show changes in custom since debut in 1919 • Compton tallies only win as swimmers bow 37-20 • Statistics point out leaders in current bruin court season • Coach makes ready for busy schedule in links campaign • Belles take Beaver in court tilt 31-27 for third triumph • Gurzynski predicts good cinder season as eight vets return • Matmen lose three due to graduation leaving huge gaps • Diamond club whips into playing shape for southern trip • Reversals highlight intramural contests as standings shift • Seniors terminate basketball careers with coach Seeders • Dr. Sturgis makes hobby of model railway system • Lee strums ballads to English students at surprise recitalhttps://digitalcommons.ursinus.edu/weekly/1587/thumbnail.jp

    The influence of music on mood and performance while driving

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    Mood can influence our everyday behaviour and people often seek to reinforce, or to alter their mood, for example by turning on music. Music listening while driving is a popular activity. However, little is known about the impact of music listening while driving on physiological state and driving performance. In the present experiment, it was investigated whether individually selected music can induce mood and maintain moods during a simulated drive. In addition, effects of positive, negative, and no music on driving behaviour and physiological measures were assessed for normal and high cognitive demanding rides. Subjective mood ratings indicated that music successfully maintained mood while driving. Narrow lane width drives increased task demand as shown in effort ratings and increased swerving. Furthermore, respiration rate was lower during music listening compared to rides without music, while no effects of music were found on heart rate. Overall, the current study demonstrates that music listening in car influences the experienced mood while driving, which in turn can impact driving behaviour. Practitioners Summary: Even though it is a popular activity, little is known about the impact of music while driving on physiological state and performance. We examined whether music can induce moods during high and low simulated drives. The current study demonstrates that in car music listening influences mood which in turn can impact driving behaviour. The current study shows that listening to music can positively impact mood while driving, which can be used to affect state and safe behaviour. Additionally, driving performance in high demand situations is not negatively affected by music

    Dysregulated signaling, proliferation and apoptosis impact on the pathogenesis of TCRγδ+ T cell large granular lymphocyte leukemia

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    TCRγδ+ T-LGL leukemia is a rare form of chronic mature T cell disorders in elderly, which is generally characterized by a persisten

    Semi-quantitative proteomics of mammalian cells upon short-term exposure to nonionizing electromagnetic fields

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    The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein-and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture
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