127 research outputs found
A Declarative Paradigm for Robust Cumulative Scheduling
International audienceThis paper investigates cumulative scheduling in uncertain environments, using constraint programming. We present a new declarative characterization of robustness, which preserves solution quality.We highlight the significance of our framework on a crane assignment problem with business constraints
Validation and clinical application of a multiplex high performance liquid chromatography - tandem mass spectrometry assay for the monitoring of plasma concentrations of 12 antibiotics in patients with severe bacterial infections.
Unpredictable pharmacokinetics of antibiotics in patients with life-threatening bacterial infections is associated with drug under- or overdosing. Therapeutic drug monitoring (TDM) may guide dosing adjustment aimed at maximizing antibacterial efficacy and minimizing toxicity. Rapid and accurate analytical methods are key for real-time TDM. Our objective was to develop a robust high-performance liquid chromatography-tandem mass spectrometry method (HPLC-MS/MS) for multiplex quantification of plasma concentrations of 12 antibiotics: imipenem/cilastatin, meropenem, ertapenem, cefepime, ceftazidime, ceftriaxone, piperacillin/tazobactam, amoxicillin, flucloxacillin, rifampicin, daptomycin.
A single extraction procedure consisting in methanol plasma protein precipitation and H <sub>2</sub> O dilution was used for all analytes. After chromatographic separation on an Acquity UPLC HSS-T3 2.1 × 50 mm, 1.8 µm (Waters®) column, quantification was performed by electro-spray ionisation-triple quadrupole mass spectrometry with selected reaction monitoring detection. Antibiotics were divided in two pools of calibration according to the frequency of analyses requests in the hospital routine antibiotic TDM program. Stable isotopically-labelled analogues were used as internal standards. A single analytical run lasted less than 9 min.
The method was validated based on FDA recommendations, including assessment of extraction yield (96-113.8%), matrix effects, and analytical recovery (86.3-99.6%). The method was sensitive (lower limits of quantification 0.02-0.5 µg/mL), accurate (intra/inter-assay bias -11.3 to +12.7%) and precise (intra/inter-assay CVs 2.1-11.5%) over the clinically relevant plasma concentration ranges (upper limits of quantification 20-160 µg/mL). The application of the TDM assay was illustrated with clinical cases that highlight the impact on patients' management of an analytical assay providing information with short turn-around time on antibiotic plasma concentration.
This simple, robust high-throughput multiplex HPLC-MS/MS assay for simultaneous quantification of plasma concentrations of 12 daily used antibiotics is optimally suited for clinically efficient real-time TDM
Chemical Composition, Antioxidant Potentials, and Calcium Oxalate Anticrystallization Activity of Polyphenol and Saponin Fractions from Argania spinosa L. Press Cake
A wide range of biological properties and a potent therapeutic and prophylactic effect on chronic diseases are all present in Argania spinosa L. press cake. The aim of this research is to valorize the anticrystallization properties against calcium oxalate crystals of Argania spinosa L. press cake fractions and identify its bioactive components. Chemical species identification was performed using GC-MS analysis. The turbidimetric model was used to investigate crystallization inhibition in vitro. Infrared spectroscopy technique was used to characterize the synthesized crystals. Furthermore, both DPPH and FRAP methods were used to assess antioxidant activity. The results show that the fractions are equally important in crystallization inhibition percentages of calcium oxalate crystals. For saponin and polyphenol fractions, the inhibition percentages are in the orders of 83.49% and 82.83%, respectively. The results of the antioxidant activity by DPPH method show that the two fractions are equally important in the elimination of free radicals; the inhibition percentages were 77.87 +/- 4.21 and 89.92 +/- 1.39 for both polyphenols and saponins, respectively. FRAP method showed that the absorbance increases proportionally with concentration, and the absorbance are almost similar for both fractions and reach maximum values in the orders of 0.52 +/- 0.07 and 0.42 +/- 0.03, respectively, for saponins and polyphenols. These findings demonstrate that both fractions are rich in bioactive chemicals and have an anticrystallization capacity, allowing them to be employed for the curative and prophylactic effects against urolithiasis.Peer reviewe
Chemical Composition, Antioxidant Potentials, and Calcium Oxalate Anticrystallization Activity of Polyphenol and Saponin Fractions from Argania spinosa L. Press Cake
A wide range of biological properties and a potent therapeutic and prophylactic effect on chronic diseases are all present in Argania spinosa L. press cake. The aim of this research is to valorize the anticrystallization properties against calcium oxalate crystals of Argania spinosa L. press cake fractions and identify its bioactive components. Chemical species identification was performed using GC–MS analysis. The turbidimetric model was used to investigate crystallization inhibition in vitro. Infrared spectroscopy technique was used to characterize the synthesized crystals. Furthermore, both DPPH and FRAP methods were used to assess antioxidant activity. The results show that the fractions are equally important in crystallization inhibition percentages of calcium oxalate crystals. For saponin and polyphenol fractions, the inhibition percentages are in the orders of 83.49% and 82.83%, respectively. The results of the antioxidant activity by DPPH method show that the two fractions are equally important in the elimination of free radicals; the inhibition percentages were 77.87 ± 4.21 and 89.92 ± 1.39 for both polyphenols and saponins, respectively. FRAP method showed that the absorbance increases proportionally with concentration, and the absorbance are almost similar for both fractions and reach maximum values in the orders of 0.52 ± 0.07 and 0.42 ± 0.03, respectively, for saponins and polyphenols. These findings demonstrate that both fractions are rich in bioactive chemicals and have an anticrystallization capacity, allowing them to be employed for the curative and prophylactic effects against urolithiasis
Chemical Composition, Antioxidant Potentials, and Calcium Oxalate Anticrystallization Activity of Polyphenol and Saponin Fractions from Argania spinosa L. Press Cake
A wide range of biological properties and a potent therapeutic and prophylactic effect on chronic diseases are all present in Argania spinosa L. press cake. The aim of this research is to valorize the anticrystallization properties against calcium oxalate crystals of Argania spinosa L. press cake fractions and identify its bioactive components. Chemical species identification was performed using GC–MS analysis. The turbidimetric model was used to investigate crystallization inhibition in vitro. Infrared spectroscopy technique was used to characterize the synthesized crystals. Furthermore, both DPPH and FRAP methods were used to assess antioxidant activity. The results show that the fractions are equally important in crystallization inhibition percentages of calcium oxalate crystals. For saponin and polyphenol fractions, the inhibition percentages are in the orders of 83.49% and 82.83%, respectively. The results of the antioxidant activity by DPPH method show that the two fractions are equally important in the elimination of free radicals; the inhibition percentages were 77.87 ± 4.21 and 89.92 ± 1.39 for both polyphenols and saponins, respectively. FRAP method showed that the absorbance increases proportionally with concentration, and the absorbance are almost similar for both fractions and reach maximum values in the orders of 0.52 ± 0.07 and 0.42 ± 0.03, respectively, for saponins and polyphenols. These findings demonstrate that both fractions are rich in bioactive chemicals and have an anticrystallization capacity, allowing them to be employed for the curative and prophylactic effects against urolithiasis
Search for right-handed W bosons in top quark decay
We present a measurement of the fraction f+ of right-handed W bosons produced
in top quark decays, based on a candidate sample of events in the
lepton+jets decay mode. These data correspond to an integrated luminosity of
230pb^-1, collected by the DO detector at the Fermilab Tevatron
Collider at sqrt(s)=1.96 TeV. We use a constrained fit to reconstruct the
kinematics of the and decay products, which allows for the
measurement of the leptonic decay angle for each event. By comparing
the distribution from the data with those for the expected
background and signal for various values of f+, we find
f+=0.00+-0.13(stat)+-0.07(syst). This measurement is consistent with the
standard model prediction of f+=3.6x10^-4.Comment: Submitted to Physical Review D Rapid Communications 7 pages, 3
figure
A search for W bb and W Higgs production in ppbar collisions at sqrt(s)=1.96 TeV
We present a search for W b \bar{b} production in p \bar{p} collisions at
sqrt{s}=1.96 TeV in events containing one electron, an imbalance in transverse
momentum, and two b-tagged jets. Using 174 pb-1 of integrated luminosity
accumulated by the D0 experiment at the Fermilab Tevatron collider, and the
standard-model description of such events, we set a 95% C.L. upper limit on W b
\bar{b}WH--$135
GeV.Comment: 7 pages, 4 figures, 1 table, submitted to Physical Review Letter
Measurement of Semileptonic Branching Fractions of B Mesons to Narrow D** States
Using the data accumulated in 2002-2004 with the DO detector in
proton-antiproton collisions at the Fermilab Tevatron collider with
centre-of-mass energy 1.96 TeV, the branching fractions of the decays B ->
\bar{D}_1^0(2420) \mu^+ \nu_\mu X and B -> \bar{D}_2^{*0}(2460) \mu^+ \nu_\mu X
and their ratio have been measured: BR(\bar{b}->B) \cdot BR(B-> \bar{D}_1^0
\mu^+ \nu_\mu X) \cdot BR(\bar{D}_1^0 -> D*- pi+) =
(0.087+-0.007(stat)+-0.014(syst))%; BR(\bar{b}->B)\cdot BR(B->D_2^{*0} \mu^+
\nu_\mu X) \cdot BR(\bar{D}_2^{*0} -> D*- \pi^+) =
(0.035+-0.007(stat)+-0.008(syst))%; and (BR(B -> \bar{D}_2^{*0} \mu^+ \nu_\mu
X)BR(D2*0->D*- pi+)) / (BR(B -> \bar{D}_1^{0} \mu^+ \nu_\mu X)\cdot
BR(\bar{D}_1^{0}->D*- \pi^+)) = 0.39+-0.09(stat)+-0.12(syst), where the charge
conjugated states are always implied.Comment: submitted to Phys. Rev. Let
Measurement of the Lifetime Difference in the B_s^0 System
We present a study of the decay B_s^0 -> J/psi phi We obtain the CP-odd
fraction in the final state at time zero, R_perp = 0.16 +/- 0.10 (stat) +/-
0.02 (syst), the average lifetime of the (B_s, B_sbar) system, tau (B_s^0)
=1.39^{+0.13}_{-0.16} (stat) ^{+0.01}_{-0.02} (syst) ps, and the relative width
difference between the heavy and light mass eigenstates, Delta Gamma/Gamma =
(Gamma_L - Gamma_H)/Gamma =0.24^{+0.28}_{-0.38} (stat) ^{+0.03}_{-0.04} (syst).
With the additional constraint from the world average of the B_s^0$lifetime
measurements using semileptonic decays, we find tau (B_s^0)= 1.39 +/- 0.06 ~ps
and Delta Gamma/\Gamma = 0.25^{+0.14}_{-0.15}. For the ratio of the B_s^0 and
B^0 lifetimes we obtain tau(B_s^0)/tau(B^0)} = 0.91 +/- 0.09 (stat) +/- 0.003
(syst).Comment: submitted to Phys. Rev. Lett. FERMILAB-PUB-05-324-
A Search for the Flavor-Changing Neutral Current Decay B0_s -> mu^+mu^- in pp(bar) Collisions at \sqrt{s} = 1.96 TeV with the D0 Detector
We present the results of a search for the flavor-changing neutral current
decay B0_s -> mu+ mu- using a data set with integrated luminosity of 240
pb^{-1} of pp(bar) collisions at sqrt{s}=1.96 TeV collected with the D0
detector in Run II of the Fermilab Tevatron collider. We find the upper limit
on the branching fraction to be Br(B0_s -> mu+ mu-) \leq 5.0 x 10^{-7} at the
95% C.L. assuming no contributions from the decay B0_d -> mu+ mu- in the signal
region. This limit is the most stringent upper bound on the branching fraction
B0_s -> mu+ mu- to date.Comment: 7 pages, 3 figures, LaTeX, to be submitted to Physical Review
Letters, minor changes to text, reference adde
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