520 research outputs found
Multiparticle Correlations In Pb--Pb Collisions At \snn=2.76 Tev
Quantum Chromodynamics, which describe the interactions of quarks and gluons, have been found not to violate global parity symmetry. However, the possibility
of local parity violations due to transitions in the vacuum state of QCD is not excluded. The effects of these parity violations could be measured in the
hot and dense medium created in the ultrarelativistic heavy ion collisions experiment conducted at the Large Hadron Collider, called a Quark-Gluon Plasma, in which
the quarks that compose most of ordinary matter are deconfined. In the strong magnetic fields which permeate the QGP in non-central collisions, parity violation
would express itself as a charge asymetry with respect to the reaction plane, a phenomenon called the Chiral Magnetic Effect.
The measurements of the charge-dependent correlations in a heavy-ion collisions allows to experimentally probe effects of the CME. These measurements
are conducted via the use of the second harmonic two-particle correlator with respect to the reaction plane,
The background affecting these measurements is the consequence of an interplay of strong anisotropic flow and correlations unrelated to the CME.
Correlations with respect to the fourth harmonic, , are insensitive to the CME and can be used to estimate
the magnitude of these background effects. In this thesis, we present results from charge-dependent correlations with respect to both the second and fourth harmonic event planes measured in Pb+Pb collisions at
TeV at the LHC using data from the ALICE detector. We also present calculations of the ratio of the fourth to second harmonics
based on the blast-wave model, which serve as a baseline to understand how these background effects scale between one harmonic and another
IS METABOLOMICS THE DIAGNOSTIC TOOL FOR MEDICAL DIAGNOSTICS OF CANCER? AN EXAMPLE BASED ON LUNG AND BREAST CANCER
Background. Metabolomics is a relatively new diagnostic tool that allows a deep insight into the body metabolism at a cellular level.
Objective. This paper provides a comprehensive view into the metabolomic methodology and shows usefulness of this approach in diagnosing and stratifying lung and breast cancers.
Methods. Literature review of metabolomics studies and its clinical application in the diagnosis of cancer-selected studies.
Results. In general, the metabolomic approach comprises three steps: 1) sampling and preparing biofluids or tissue homogenates, 2) identification of low-molecular weight compounds up to 1.0 kDa using nuclear magnetic resonance, mostly 1H-NMR and/or mass spectrometry, and finally 3) data processing and analysing. It is possible to identify a set of metabolites which is specific for a certain metabolic status (the metabolic fingerprint). Furthermore, this set of metabolites provides information of possible pathomechanisms involved in the disease process i.e. information about the disease etiology. It has been proven that the change in metabolome precedes other biomarkers of the disease; not only clinical symptoms but other laboratory findings as well. Consequently, this approach, if sufficiently validated, seems to be very promising especially in screening and early diagnosing.
Conclusions. It was demonstrated that metabolomic approach allows to discriminate patients with cancer from healthy persons, as well as to differentiate between clinical stages of the cancer
Rich magnetic chemistry of cobalt(II) complexes with N-phosphorylthioureas. Crystal structure and solution1H NMR spectral properties
Structure and magnetic properties of CoII complexes with N-phosphorylthiourea derivatives [RC(S)NHP(O)(OiPr)2] (HL) [Co {Et2NC(S)NP(O)(OzPr)2}2] (1), [Co [(PrNHC(S)NP(O)-(OiPr)2}2] (2), [Co {[/BuNHC(S)NP(O)(OiPr) 2}2] (3), [Co{p-MeOC6H4NHC(S)NP(O) (O(Pr)2}2] (4), [Co{P-BrC6H4NHC-(S) NP(O)(O(Pr)2}2] (5) were investigated. Paramagnetic shifts in the 1H NMR spectrum were observed for high-spin CoII complexes with HL, incorporating amidophosphate moiety C(S)NP(O). The thermal dependence of the magnetic susceptibility has shown that the extended materials 2, 3 and 5 show ferromagnetic exchange between distorted tetrahedral metal atoms, while in complex 4 antiferromagnetic behavior takes place. Compound 1 behaves as a spincanted ferromagnet, an antiferromagnetic ordering taking place below a critical temperature, Tc = 175 K. Complex 2 was investigated by single crystal X-ray diffraction. The cobalt(II) atom in complex 2 is in distorted tetrahedral CoO2S2 environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated ligands. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA
Coordination diversity of N-phosphoryl-N′-phenylthiourea (LH) towards CoII, NiII and PdII cations: Crystal structure of ML2-N,S and ML2-O,S chelates
Thiourea, PhNHC(S)NHP(O)(OPri)2 (LH) chelates of CoII, NiII, and PdII ions have been obtained and investigated by single-crystal X-ray diffraction, UV, IR, NMR spectroscopy, and EI mass-spectrometry. The unusual 1,3-N,S-coordination via sulfur and NP(O) nitrogen atoms has been found in the trans-square-planar NiL2 and PdL2 complexes, whereas the 1,5-O,S-coordination is realized in the tetrahedral CoL2 complex. DFT calculations have revealed significant stabilization of the 1,3-N,S-structures due to stronger crystal field and the NH-O{double bond, long}P hydrogen bonds. © 2006 Elsevier B.V. All rights reserved
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
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