Showing papers by "University of Mons published in 2011"
TL;DR: This review covers recent advances in the development of SPions together with their possibilities and limitations from fabrication to application in drug delivery and the state-of-the-art synthetic routes and surface modification of desired SPIONs for drug delivery purposes.
1,557 citations
TL;DR: Protein Nanoparticle Interactions: Opportunities and Challenges
Abstract: Protein Nanoparticle Interactions: Opportunities and Challenges Morteza Mahmoudi,* Iseult Lynch, Mohammad Reza Ejtehadi, Marco P. Monopoli, Francesca Baldelli Bombelli, and Sophie Laurent National Cell Bank, Pasteur Institute of Iran, Tehran, Iran Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran School of Chemistry and Chemical Biology & Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland Department of Physics, Sharif University of Technology, Tehran, Iran School of Pharmacy, UEA, Norwich Research Park, Norwich,U.K. Department of General, Organic, and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau 19, B-7000 Mons, Belgium
1,214 citations
TL;DR: In this review, the limitations and recent advances in the development of superparamagnetic iron oxide nanoparticles for hyperthermia are presented.
1,161 citations
TL;DR: In this article, the transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transversal momentum resolution.
Abstract: Measurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centre-of-mass energy of 7TeV, corresponding to an integrated luminosity of 36pb−1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different methods to reconstruct jets: a calorimeter-based approach, the ``Jet-Plus-Track'' approach, which improves the measurement of calorimeter jets by exploiting the associated tracks, and the ``Particle Flow'' approach, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant subdetectors
750 citations
TL;DR: In this article, the authors studied the effect of collision centrality on the transverse momentum of PbPb collisions at the LHC with a data sample of 6.7 inverse microbarns.
Abstract: Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 inverse microbarns. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet transverse momentum = 120 GeV/c) up to the statistical limit of the available data sample (jet transverse momentum approximately 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.
621 citations
TL;DR: It was clearly evidenced that the chemical grafting of CNW enhances their compatibility with the polymeric matrix and thus improves the final properties of the nanocomposites.
350 citations
TL;DR: This work proposes a new parallel bi-objective hybrid genetic algorithm that takes into account, not only makespan, but also energy consumption, and focuses on the island parallel model and the multi-start parallel model.
327 citations
TL;DR: In this article, the wrinkling of a rigid membrane attached to a soft substrate is described within a framework similar to that used for the parametric resonance of nonlinear oscillators.
Abstract: The complex wrinkling patterns produced when a sheet or membrane is compressed are often difficult to predict. Observations of unexpected spatial period-doubling bifurcation instability in the wrinkling of a rigid membrane attached to a soft substrate can be described within a framework similar to that used for the parametric resonance of nonlinear oscillators.
321 citations
TL;DR: Evaluating the toxicities of three forms of superparamagnetic iron oxide nanoparticles of various surface chemistries revealed that SPIONs-COOH altered genes associated with cell proliferative responses due to their reactive oxygen species (ROS) properties.
Abstract: In the last few decades, nanoparticles (NPs) have been recognized as promising candidates for starting a new revolution in science and technology due to their unusual properties, attracting the attention of physicists, chemists, biologists, and engineers. The aim of this study is to evaluate the toxicities (at both cellular and molecular levels) of three forms of superparamagnetic iron oxide nanoparticles (SPIONs) of various surface chemistries (COOH, plain, and NH2) through the comparison with gene expression patterns of three cell types (i.e., human heart, brain, and kidney). For this purpose, both an MTT assay and a DNA microarray analysis were applied in three human cell lines—HCM (heart), BE-2-C (brain), and 293T (kidney)—under the exposure to SPIONs-COOH, SPIONs-NH2, and bare SPIONs. The specific gene alteration and hierarchical clustering revealed that SPIONs-COOH altered genes associated with cell proliferative responses due to their reactive oxygen species (ROS) properties. It was also found that...
320 citations
TL;DR: Effect of Nanoparticles on the Cell Life Cycle Morteza Mahmoudi,* Kayhan Azadmanesh, Mohammad A. Shokrgozar, W. Shane Journeay, and Sophie Laurent
Abstract: Effect of Nanoparticles on the Cell Life Cycle Morteza Mahmoudi,* Kayhan Azadmanesh, Mohammad A. Shokrgozar, W. Shane Journeay, and Sophie Laurent National Cell Bank, Pasteur Institute of Iran, Tehran, 1316943551 Iran Virology Department, Pasteur Institute of Iran, Tehran, 1316943551 Iran Nanotechnology Toxicology Consulting & Training, Inc., Nova Scotia, Canada Faculty of Medicine, Dalhousie Medical School, Dalhousie University, Halifax, Nova Scotia, Canada Department of General, Organic, and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau, 19, B-7000 Mons, Belgium Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
311 citations
TL;DR: In this paper, a search for events with jets and missing transverse energy is performed in a data sample of pp collisions collected at 7 TeV by the CMS experiment at the LHC.
Abstract: A search for events with jets and missing transverse energy is performed in a data sample of pp collisions collected at sqrt(s) = 7 TeV by the CMS experiment at the LHC. The analyzed data sample corresponds to an integrated luminosity of 1.14 inverse femtobarns. In this search, a kinematic variable, alphaT, is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. No excess of events over the standard model expectation is found. Exclusion limits in the parameter space of the constrained minimal supersymmetric extension of the standard model are set. In this model, squark masses below 1.1 TeV are excluded at 95% CL. Gluino masses below 1.1 TeV are also ruled out at 95% CL for values of the universal scalar mass parameter below 500 GeV.
TL;DR: Existing modeling frameworks and methodologies for parameter estimation and model validation in the field of anaerobic digestion processes are discussed, intentionally focusing on simple but efficient methods.
TL;DR: The physics of various imaging methods, including MRI, optical techniques, X-rays and CT will be described, and the effect of NPs on the improvement of the mentioned non-invasive imaging methods will be discussed together with their advantages and disadvantages.
Abstract: In recent years, the production of nanoparticles (NPs) and exploration of their unusual properties have attracted the attention of physicists, chemists, biologists and engineers. Interest in NPs arises from the fact that the mechanical, chemical, electrical, optical, magnetic, electro-optical and magneto-optical properties of these particles are different from their bulk properties and depend on the particle size. There are numerous areas where nanoparticulate systems are of scientific and technological interest, particularly in biomedicine where the emergence of NPs with specific properties (e.g. magnetic and fluorescence) for contrast agents can lead to advancing the understanding of biological processes at the biomolecular level. This review will cover a full description of the physics of various imaging methods, including MRI, optical techniques, X-rays and CT. In addition, the effect of NPs on the improvement of the mentioned non-invasive imaging methods will be discussed together with their advantages and disadvantages. A detailed discussion will also be provided on the recent advances in imaging agents, such as fluorescent dye-doped silica NPs, quantum dots, gold- and engineered polymeric-NPs, superparamagnetic iron oxide NPs (SPIONs), and multimodal NPs (i.e. nanomaterials that are active in both MRI and optical methods), which are employed to overcome many of the limitations of conventional contrast agents (e.g. gadolinium).
Proceedings Article•
28 Aug 2011TL;DR: In this article, a method using harmonic information in the residual signal is presented for pitch tracking in noisy conditions, which is used both for pitch estimation, as well as for determining the voicing segments of speech.
Abstract: This paper focuses on the problem of pitch tracking in noisy conditions. A method using harmonic information in the residual signal is presented. The proposed criterion is used both for pitch estimation, as well as for determining the voicing segments of speech. In the experiments, the method is compared to six state-of-the-art pitch trackers on the Keele and CSTR databases. The proposed technique is shown to be particularly robust to additive noise, leading to a significant improvement in adverse conditions. Index Terms: fundamental frequency, pitch tracking, pitch estimation, voicing decisions
Vardan Khachatryan, Albert M. Sirunyan, Armen Tumasyan, Wolfgang Adam1 +2193 more•Institutions (152)
TL;DR: In this article, the authors measured the Upsilon production cross section in proton-proton collisions at 7 TeV using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.81 nb.
Abstract: The Upsilon production cross section in proton-proton collisions at sqrt(s) = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range |y|<2, we find the product of the Upsilon(1S) production cross section and branching fraction to dimuons to be sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = 7.37 +/- 0.13^{+0.61}_{-0.42}\pm 0.81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Upsilon(1S) production. If the Upsilon(1S) production polarization is fully transverse or fully longitudinal the cross section changes by about 20%. We also report the measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections as a function of transverse momentum and rapidity.
TL;DR: In this paper, a measurement of W and Z production cross sections in pp collisions at 7 TeV is presented, where electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 inverse picobarns.
Abstract: A measurement of inclusive W and Z production cross sections in pp collisions at sqrt(s)=7 TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 inverse picobarns. The measured inclusive cross sections are sigma(pp-> WX) B(W-> l nu) = 10.30 +/- 0.02 (stat.) +/- 0.10 (syst.) +/- 0.10 (th.) +/- 0.41 (lumi.) nb and sigma(pp -> ZX) B(Z-> l^+l^-) = 0.974 +/- 0.007 (stat.) +/- 0.007 (syst.) +/- 0.018 (th.) +/- 0.039 (lumi.) nb, limited to the dilepton invariant mass range 60 to 120 GeV. The luminosity-independent cross section ratios are [sigma(pp->WX) B(W-> l nu)]/[sigma(pp-> ZX) B(Z->l^+l^-)] = 10.54 +/- 0.07 (stat.) +/- 0.08 (syst.) +/- 0.16 (th.) and [sigma(pp->W^+X) B(W^+ -> l^+nu)] / [sigma(pp->W^- X) B(W^- -> l^- nu)] = 1.421 +/- 0.006 (stat.) +/- 0.014 (syst.) +/- 0.029 (th.). The measured values agree with next-to-next-to-leading order QCD cross section calculations based on recent parton distribution functions.
TL;DR: A metallic oxide nanofiller, that is, ZnO, has been dispersed into PLA without detrimental polyester degradation yielding PLA/ZnO nanocomposites directly suitable for producing films and fibers.
Vardan Khachatryan, Albert M. Sirunyan, Armen Tumasyan, Wolfgang Adam1 +2184 more•Institutions (150)
TL;DR: In this article, the W and Z boson production cross sections in pp collisions at 7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC.
Abstract: Measurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.
TL;DR: In this article, a reactive blending of anhydride-grafted PLA (MAG-PLA) copolymer with PEG, with chains terminated with hydroxyl groups, was performed.
Vardan Khachatryan, Milan Nikolic1, Robin Erbacher1, C. A. Carrillo Montoya +2169 more•Institutions (155)
TL;DR: In this article, a search for supersymmetry with R-parity conservation in proton-proton collisions at a centre-of-mass energy of 7 TeV is presented.
TL;DR: In this paper, a comparison of the relative yields of upsilon resonances in the mu(+) mu(-) decay channel in PbPb and pp collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV, is performed with data collected with the CMS detector at the LHC.
Abstract: A comparison of the relative yields of Upsilon resonances in the mu(+) mu(-) decay channel in PbPb and pp collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV, is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4 GeV/c and pseudorapidity below 2.4, the double ratio of the Upsilon(2S) and Upsilon(3S) excited states to the Upsilon(1S) ground state in PbPb and pp collisions,(Upsilon(2S+3S)/Upsilon(1S)[PbPb])/(Upsilon(2S+3S)/Upsilon(1S)[pp]), is found to be 0.31 - 0.15 + 0.19 (stat.) +/- 0.03 (syst.). The probability to obtain the measured value, or lower, if the true double ratio is unity, has been calculated to be less than 1%.
TL;DR: In this paper, a measurement of the atmospheric muon neutrino energy spectrum from 100 GeV to 400 TeV was performed using a data sample of about 18, 000 up-going atmospheric neutrinos events in IceCube.
Abstract: A measurement of the atmospheric muon neutrino energy spectrum from 100 GeV to 400 TeV was performed using a data sample of about 18 000 up-going atmospheric muon neutrino events in IceCube. Boosted decision trees were used for event selection to reject misreconstructed atmospheric muons and obtain a sample of up-going muon neutrino events. Background contamination in the final event sample is less than 1%. This is the first measurement of atmospheric neutrinos up to 400 TeV, and is fundamental to understanding the impact of this neutrino background on astrophysical neutrino observations with IceCube. The measured spectrum is consistent with predictions for the atmospheric nu(mu) + (nu) over bar (mu) flux.
TL;DR: Co-deposition of Au nanoparticles with WO(3) nanoneedles has been used to deposit a sensing layer directly onto gas sensor substrates providing devices with a six-fold increase in response to low concentrations of a test analyte (ethanol).
TL;DR: The exposure of human transferrin to SPIONs results in the release of iron, which changes the main function of the protein, which is the transport of iron among cells, indicating irreversible changes in transferrin conformation: from a compact to an open structure.
Abstract: The understanding of the interactions between nanomaterials and proteins is of extreme importance in medicine. In a biological fluid, proteins can adsorb and associate with nanoparticles, which can have significant impact on the biological behavior of the proteins and the nanoparticles. We report here on the interactions of iron saturated human transferrin protein with both bare and polyvinyl alcohol coated superparamagnetic iron oxide nanoparticles (SPIONs). The exposure of human transferrin to SPIONs results in the release of iron, which changes the main function of the protein, which is the transport of iron among cells. After removal of the magnetic nanoparticles, the original protein conformation is not recovered, indicating irreversible changes in transferrin conformation: from a compact to an open structure.
TL;DR: In this paper, the impact of the covalent grafting of CNWr surface on thermo-mechanical properties of the commercial poly(e-caprolactone) matrix was investigated.
TL;DR: In this paper, the authors provide a critical overview of the current computational techniques used to assess the morphology of organic:organic heterojunctions; they highlight the compromises that are necessary to handle large systems and multiple time scales while preserving the atomistic details required for subsequent computations of the electronic and optical properties.
Abstract: We report on the recent progress achieved in modeling the electronic processes that take place at interfaces between π-conjugated materials in organic opto-electronic devices. First, we provide a critical overview of the current computational techniques used to assess the morphology of organic:organic heterojunctions; we highlight the compromises that are necessary to handle large systems and multiple time scales while preserving the atomistic details required for subsequent computations of the electronic and optical properties. We then review some recent theoretical advances in describing the ground-state electronic structure at heterojunctions between donor and acceptor materials and highlight the role played by charge-transfer and long-range polarization effects. Finally, we discuss the modeling of the excited-state electronic structure at organic:organic interfaces, which is a key aspect in the understanding of the dynamics of photoinduced electron-transfer processes.
Vardan Khachatryan, Albert M. Sirunyan, Armen Tumasyan, Wolfgang Adam1 +2222 more•Institutions (151)
TL;DR: In this article, the multiplicity distribution of primary charged hadron multiplicity distributions for non-single-diffractive events in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |eta|<0.5 to |eta |<2.4.
Abstract: Measurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of sqrt(s) = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |eta|<0.5 to |eta|<2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The multiplicity distribution at sqrt(s) = 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean multiplicity with sqrt(s) is underestimated by most event generators. The average transverse momentum as a function of the multiplicity is also presented. The measurement of higher-order moments of the multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies.
TL;DR: Electrochemistry, absorption, and fluorescence spectra indicate that the HOMO-LUMO gap of the nanoring is less than that of the linear hexamer and less than those of the corresponding polymer.
Abstract: Linear π-conjugated oligomers have been widely investigated, but the behavior of the corresponding cyclic oligomers is poorly understood, despite the recent synthesis of π-conjugated macrocycles such as [n]cycloparaphenylenes and cyclo[n]thiophenes. Here we present an efficient template-directed synthesis of a π-conjugated butadiyne-linked cyclic porphyrin hexamer directly from the monomer. Small-angle X-ray scattering data show that this nanoring is shape-persistent in solution, even without its template, whereas the linear porphyrin hexamer is relatively flexible. The crystal structure of the nanoring–template complex shows that most of the strain is localized in the acetylenes; the porphyrin units are slightly curved, but the zinc coordination sphere is undistorted. The electrochemistry, absorption, and fluorescence spectra indicate that the HOMO–LUMO gap of the nanoring is less than that of the linear hexamer and less than that of the corresponding polymer. The nanoring exhibits six one-electron reduc...
TL;DR: Novel monodispersed silica-coated iron oxide nanoparticles are promising materials for medical imaging, cell tracking and other biomedical applications and display excellent magnetic properties.
Vardan Khachatryan, Albert M. Sirunyan, Armen Tumasyan, Wolfgang Adam1 +2184 more•Institutions (152)
TL;DR: In this article, the production of J/psi mesons from b-hadron decays at the LHC was studied in pp collisions at 6.5 to 30 GeV/c and in three rapidity ranges.
Abstract: The production of J/psi mesons is studied in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 inverse nanobarns. The J/psi differential cross section is determined, as a function of the J/psi transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/psi) component. Integrated over J/psi transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range |y| < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 \pm 2.1 (stat.) \pm 3.0 (syst.) \pm 7.8(luminosity) nb for prompt J/psi mesons assuming unpolarized production and 26.0 \pm 1.4 (stat.) \pm 1.6 (syst.) \pm 2.9 (luminosity) nb for J/psi mesons from b-hadron decays.