1,011 research outputs found

    Surface activated chemical ionization - Electrospray mass spectrometry in the analysis of urinary thiodiglycolic acid

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    RATIONALE Thiodiglycolic acid (TDGA) is a urinary metabolite of the oxazaphosphorine class of chemotherapeutics, in particular of ifosfamide. Ifosfamide metabolism generates chloroacetaldehyde (CAA), a toxic compound associated with neurotoxicity, nephrotoxicity, urotoxicity and cardiotoxicity. CAA, in turn, interacts with cellular thiol groups leading to GSH depletion, cell death and generation of thiodiglycolic acid (TDGA), as a final product. TDGA is mainly excreted in the urine. The ability to accurately measure TDGA in urine, therefore, will be a useful way of monitoring the ifosfamide exposure during chemotherapy. METHODS TDGA in urine samples was measured with liquid chromatograpy coupled to mass spectrometry (LC-MS) by means of a novel Surface Activated Chemical Ionization - Electrospray (SACI-ESI) or a classical ESI ion source alone. RESULTS The SACI - ESI and ESI alone based methods for analysis of urinary TDGA were optimized and compared. A strong reduction in matrix effect together with enhanced quantification performances was obtained with the SACI \u2013 ESI when compared with the ESI. In particular, an increase in quantification precision (from 85 to 95%) and accuracy (from 59 to 90%) were observed, which allowed for optimal detection of TDGA. CONCLUSIONS The LC-SACI-ESI-MS approach provides a very sensitive and quantitative method for the analysis of TDGA. Thanks to sensitivity enhancement and matrix effect reduction, the SACI \u2013 ESI enables the use of a relatively low cost ion-trap mass spectrometer in the analysis of this toxicity biomarker in urine. Due to these characteristics, this approach would constitutes an invaluable tool in the clinical laboratory, for measuring TDGA and other toxicity related biomarkers of chemotherapy with proper sensitivity and accuracy

    Real Potential

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    There\u27s a student in my philosophy class who has real potential. I might express this thought in any of the following ways: She is potentially a philosopher ; She is a potential philosopher ; She has the potential to be a philosopher. The first way uses a cognate of potential as an adverb to modify is. The second ways uses potential as an adjective to modify philosopher. However, the third way uses potential as a noun to refer to something that the student has. What kind of thing is this potential? One worry about even asking this question is that this nominalization of the adjective potential suggests a metaphysical picture that is an artifact of language. This is even more strongly suggested by the less ambiguous nominalization potentiality. Once we have the term potentiality, we have a new kind of entity to countenance, and questions about its nature arise. One might argue, just because we use the word potentiality, we should not think that it refers to a thing that someone can have. There is something disingenuous about such an argument. It proceeds as if the adverbial and adjectival uses of potential are unproblematic, and questions only arise with the nominalization. But it is not obvious what it means to potentially be something, or what it means to be a potential something. To say that someone is potentially a philosopher is to talk about a way of being that falls short of actuality. And a potential philosopher is not a kind of philosopher at all. So what is it? Each of the three above formulations is a modal claim. If there is anything philosophical puzzling about a potentiality claim, it is not going to go away by translating it into an equivalent modal claim. In this chapter I defend the existence of potentialities against anti-realist arguments, and make a proposal as to their nature. The proposal, in short, is that potentialities are properties, specifically dispositions, though more needs to be said about properties and dispositions. I will do this in Part I. In Part II, I will address two lines of argument against potentialities: that they are reducible, and that they are causally inert

    One-year treatment with mometasone furoate in chronic obstructive pulmonary disease

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    Many patients with chronic obstructive pulmonary disease (COPD) are treated with twice daily (BID) inhaled corticosteroids (ICS). This study evaluated whether daily PM mometasone furoate administered via a dry powder inhaler (MF-DPI) was equally effective compared to twice daily dosing

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay

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    We reconstruct the rare decays B+K+μ+μB^+ \to K^+\mu^+\mu^-, B0K(892)0μ+μB^0 \to K^{*}(892)^0\mu^+\mu^-, and Bs0ϕ(1020)μ+μB^0_s \to \phi(1020)\mu^+\mu^- in a data sample corresponding to 4.4fb14.4 {\rm fb^{-1}} collected in ppˉp\bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} by the CDF II detector at the Fermilab Tevatron Collider. Using 121±16121 \pm 16 B+K+μ+μB^+ \to K^+\mu^+\mu^- and 101±12101 \pm 12 B0K0μ+μB^0 \to K^{*0}\mu^+\mu^- decays we report the branching ratios. In addition, we report the measurement of the differential branching ratio and the muon forward-backward asymmetry in the B+B^+ and B0B^0 decay modes, and the K0K^{*0} longitudinal polarization in the B0B^0 decay mode with respect to the squared dimuon mass. These are consistent with the theoretical prediction from the standard model, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the Bs0ϕμ+μdecayandmeasureitsbranchingratioB^0_s \to \phi\mu^+\mu^- decay and measure its branching ratio {\mathcal{B}}(B^0_s \to \phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}using using 27 \pm 6signalevents.Thisiscurrentlythemostrare signal events. This is currently the most rare B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let
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