Base de dados : MEDLINE
Pesquisa : G01.238 [Categoria DeCS]
Referências encontradas : 128 [refinar]
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[PMID]:25353517
[Au] Autor:Lima TA; Ishikawa MS; Martinho HS
[Ad] Endereço:Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André -SP 09210-580, Brazil.
[Ti] Título:Boson peak as a probe of quantum effects in a glassy state of biomolecules: the case of L-cysteine.
[So] Source:Phys Rev E Stat Nonlin Soft Matter Phys;89(2):022715, 2014 Feb.
[Is] ISSN:1550-2376
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Some physical properties of hydrated biomolecules, e.g., the occurrence of a boson peak, have been recognized to resemble those of glassy states. The present work shows that quantum fluctuations play a fundamental role in describing the glassy state of biomolecules, particularly at lower hydration levels. There is a linear relationship between the quantumness and the slope of the temperature dependence of the boson peak frequency, which is used to classify the extent of quantum contributions to the glassy state of glasses in general. Lastly, we demonstrate that the boson peak two-band spectral structure that is observed in some cases can be directly linked to the anisotropy of the elastic properties of the material. The amino acid L-cysteine is studied in detail. The findings are compared with previously reported data for other macromolecules.
[Mh] Termos MeSH primário: Biopolímeros/química
Cisteína/química
Interações de Partículas Elementares
Modelos Químicos
Modelos Estatísticos
Teoria Quântica
[Mh] Termos MeSH secundário: Simulação por Computador
Transição de Fase
Temperatura Ambiente
Vibração
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Biopolymers); K848JZ4886 (Cysteine)
[Em] Mês de entrada:1511
[Cu] Atualização por classe:141030
[Lr] Data última revisão:
141030
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141030
[St] Status:MEDLINE


  2 / 128 MEDLINE  
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[PMID]:24074929
[Au] Autor:Suit H
[Ad] Endereço:Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
[Ti] Título:Proton: the particle.
[So] Source:Int J Radiat Oncol Biol Phys;87(3):555-61, 2013 Nov 01.
[Is] ISSN:1879-355X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.
[Mh] Termos MeSH primário: Prótons
[Mh] Termos MeSH secundário: Fenômenos Astronômicos
Interações de Partículas Elementares
Partículas Elementares/história
História do Século XIX
História do Século XX
História do Século XXI
História Antiga
Prótons/classificação
Prótons/história
[Pt] Tipo de publicação:HISTORICAL ARTICLE; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Protons)
[Em] Mês de entrada:1311
[Cu] Atualização por classe:161125
[Lr] Data última revisão:
161125
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:131001
[St] Status:MEDLINE


  3 / 128 MEDLINE  
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[PMID]:24074074
[Au] Autor:Sandilya S; Trabelsi K; Mohanty GB; Adachi I; Aihara H; Asner DM; Aushev T; Aziz T; Bakich AM; Bala A; Bhardwaj V; Bhuyan B; Bondar A; Bonvicini G; Bozek A; Bracko M; Browder TE; Chen P; Cheon BG; Chilikin K; Chistov R; Cho K; Chobanova V; Choi SK; Choi Y; Cinabro D; Dalseno J; Dingfelder J; Dolezal Z; Drutskoy A; Dutta D; Eidelman S; Farhat H; Fast JE; Feindt M; Ferber T; Frey A; Gaur V; Gabyshev N; Ganguly S; Gillard R; Goh YM; Golob B; Haba J; Hara T; Hayasaka K; Hayashii H; Hoshi Y; Hou WS; Hsiung YB; Belle Collaboration
[Ad] Endereço:Tata Institute of Fundamental Research, Mumbai 400005.
[Ti] Título:Search for bottomonium states in exclusive radiative Υ(2S) decays.
[So] Source:Phys Rev Lett;111(11):112001, 2013 Sep 13.
[Is] ISSN:1079-7114
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We search for bottomonium states in Υ(2S) → (bb)γ decays with an integrated luminosity of 24.7 fb(-1) recorded at the Υ(2S) resonance with the Belle detector at KEK, containing (157.8±3.6)×10(6) Υ(2S) events. The (bb) system is reconstructed in 26 exclusive hadronic final states composed of charged pions, kaons, protons, and K(S)(0) mesons. We find no evidence for the state recently observed around 9975 MeV (X(bb)) in an analysis based on a data sample of 9.3×10(6) Υ(2S) events collected with the CLEO III detector. We set a 90% confidence level upper limit on the branching fraction B[Υ(2S) → X(bb)γ] × ∑(i)B[X(bb) → h(i)] < 4.9×10(-6), summed over the exclusive hadronic final states employed in our analysis. This result is an order of magnitude smaller than the measurement reported with CLEO data. We also set an upper limit for the ηb(1S) state of B[Υ(2S) → ηb(1S)γ] × ∑(i)B[ηb(1S) → h(i)] < 3.7×10(-6).
[Mh] Termos MeSH primário: Interações de Partículas Elementares
Modelos Teóricos
Física Nuclear/métodos
[Mh] Termos MeSH secundário: Método de Monte Carlo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Em] Mês de entrada:1311
[Cu] Atualização por classe:130930
[Lr] Data última revisão:
130930
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:131001
[St] Status:MEDLINE


  4 / 128 MEDLINE  
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[PMID]:23848610
[Au] Autor:Falco P
[Ad] Endereço:Department of Mathematics, California State University, Northridge, California 91330, USA.
[Ti] Título:Interacting fermions picture for dimer models.
[So] Source:Phys Rev E Stat Nonlin Soft Matter Phys;87(6):060101, 2013 Jun.
[Is] ISSN:1550-2376
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Recent numerical results on classical dimers with weak aligning interactions have been theoretically justified via a Coulomb gas representation of the height random variable. Here, we propose a completely different representation, the interacting fermions picture, which avoids some difficulties of the Coulomb gas approach and provides a better account of the numerical findings. Besides, we observe that the Peierls argument explains the behavior of the system in the strong interaction case.
[Mh] Termos MeSH primário: Dimerização
Interações de Partículas Elementares
Partículas Elementares
Gases/química
Modelos Químicos
Modelos Moleculares
Eletricidade Estática
[Mh] Termos MeSH secundário: Algoritmos
Simulação por Computador
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Gases)
[Em] Mês de entrada:1411
[Cu] Atualização por classe:130715
[Lr] Data última revisão:
130715
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130716
[St] Status:MEDLINE


  5 / 128 MEDLINE  
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[PMID]:23765419
[Au] Autor:Volkoff TJ; Whaley KB
[Ad] Endereço:Berkeley Quantum Information and Computation Center, UC Berkeley, Berkeley, CA 94720, USA. volkoff@berkeley.edu
[Ti] Título:Quantum dynamics of local phase differences between reservoirs of driven interacting bosons separated by simple aperture arrays.
[So] Source:J Phys Condens Matter;25(27):275602, 2013 Jul 10.
[Is] ISSN:1361-648X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We present a derivation of the effective action for the relative phase of driven, aperture-coupled reservoirs of weakly-interacting condensed bosons from a (3 + 1)D microscopic model with local U(1) gauge symmetry. We show that inclusion of local chemical potential and driving velocity fields as a gauge field allows derivation of the hydrodynamic equations of motion for the driven macroscopic phase differences across simple aperture arrays. For a single aperture, the current-phase equation for driven flow contains sinusoidal, linear and current-bias contributions. We compute the renormalization group (RG) beta function of the periodic potential in the effective action for small tunneling amplitudes and use this to analyze the temperature dependence of the low-energy current-phase relation, with application to the transition from linear to sinusoidal current-phase behavior observed in experiments by Hoskinson et al (2006 Nature Phys. 2 23-6) for liquid (4)He driven through nanoaperture arrays. Extension of the microscopic theory to a two-aperture array shows that interference between the microscopic tunneling contributions for individual apertures leads to an effective coupling between apertures which amplifies the Josephson oscillations in the array. The resulting multiaperture current-phase equations are found to be equivalent to a set of equations for coupled pendula, with microscopically derived couplings.
[Mh] Termos MeSH primário: Interações de Partículas Elementares
Hidrodinâmica
Análise em Microsséries
Modelos Teóricos
Teoria Quântica
[Mh] Termos MeSH secundário: Transição de Fase
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Em] Mês de entrada:1401
[Cu] Atualização por classe:130619
[Lr] Data última revisão:
130619
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130615
[St] Status:MEDLINE
[do] DOI:10.1088/0953-8984/25/27/275602


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[PMID]:23473130
[Au] Autor:Chatrchyan S; Khachatryan V; Sirunyan AM; Tumasyan A; Adam W; Aguilo E; Bergauer T; Dragicevic M; Erö J; Fabjan C; Friedl M; Frühwirth R; Ghete VM; Hammer J; Hörmann N; Hrubec J; Jeitler M; Kiesenhofer W; Knünz V; Krammer M; Krätschmer I; Liko D; Mikulec I; Pernicka M; Rahbaran B; Rohringer C; Rohringer H; Schöfbeck R; Strauss J; Taurok A; Waltenberger W; Wulz CE; Mossolov V; Shumeiko N; Suarez Gonzalez J; Bansal M; Bansal S; Cornelis T; De Wolf EA; Janssen X; Luyckx S; Mucibello L; Ochesanu S; Roland B; Rougny R; Selvaggi M; Van Haevermaet H; Van Mechelen P; Van Remortel N; Van Spilbeeck A; CMS Collaboration
[Ad] Endereço:Yerevan Physics Institute, Yerevan, Armenia.
[Ti] Título:Measurement of the Υ1S, Υ2S, and Υ3S polarizations in pp collisions at sqrt[s] = 7 TeV.
[So] Source:Phys Rev Lett;110(8):081802, 2013 Feb 22.
[Is] ISSN:1079-7114
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The polarizations of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at sqrt[s] = 7 TeV, using a data sample of Υ(nS) → µ +µ- decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9 fb(-1). The dimuon decay angular distributions are analyzed in three different polarization frames. The polarization parameters λ[symbol see text], λ(φ), and λ([symbol see text]φ), as well as the frame-invariant quantity λ, are presented as a function of the Υ(nS) transverse momentum between 10 and 50 GeV, in the rapidity ranges |y|<0.6 and 0.6<|y|<1.2. No evidence of large transverse or longitudinal polarizations is seen in the explored kinematic region.
[Mh] Termos MeSH primário: Interações de Partículas Elementares
Mésons
Modelos Teóricos
Física Nuclear/métodos
Prótons
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Protons)
[Em] Mês de entrada:1305
[Cu] Atualização por classe:130311
[Lr] Data última revisão:
130311
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130312
[St] Status:MEDLINE


  7 / 128 MEDLINE  
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[PMID]:23473129
[Au] Autor:Chatrchyan S; Khachatryan V; Sirunyan AM; Tumasyan A; Adam W; Aguilo E; Bergauer T; Dragicevic M; Erö J; Fabjan C; Friedl M; Frühwirth R; Ghete VM; Hammer J; Hörmann N; Hrubec J; Jeitler M; Kiesenhofer W; Knünz V; Krammer M; Krätschmer I; Liko D; Mikulec I; Pernicka M; Rahbaran B; Rohringer C; Rohringer H; Schöfbeck R; Strauss J; Taurok A; Waltenberger W; Walzel G; Widl E; Wulz CE; Mossolov V; Shumeiko N; Suarez Gonzalez J; Bansal M; Bansal S; Cornelis T; De Wolf EA; Janssen X; Luyckx S; Mucibello L; Ochesanu S; Roland B; Rougny R; Selvaggi M; Staykova Z; Van Haevermaet H; CMS Collaboration
[Ad] Endereço:Yerevan Physics Institute, Yerevan, Armenia.
[Ti] Título:Search for pair production of third-generation leptoquarks and top squarks in pp collisions at sqrt[s] = 7 TeV.
[So] Source:Phys Rev Lett;110(8):081801, 2013 Feb 22.
[Is] ISSN:1079-7114
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Results are presented from a search for the pair production of third-generation scalar and vector leptoquarks, as well as for top squarks in R-parity-violating supersymmetric models. In either scenario, the new, heavy particle decays into a τ lepton and a b quark. The search is based on a data sample of pp collisions at sqrt[s] = 7 TeV, which is collected by the CMS detector at the LHC and corresponds to an integrated luminosity of 4.8 fb(-1). The number of observed events is found to be in agreement with the standard model prediction, and exclusion limits on mass parameters are obtained at the 95% confidence level. Vector leptoquarks with masses below 760 GeV are excluded and, if the branching fraction of the scalar leptoquark decay to a τ lepton and a b quark is assumed to be unity, third-generation scalar leptoquarks with masses below 525 GeV are ruled out. Top squarks with masses below 453 GeV are excluded for a typical benchmark scenario, and limits on the coupling between the top squark, τ lepton, and b quark, λ(333)(') are obtained. These results are the most stringent for these scenarios to date.
[Mh] Termos MeSH primário: Interações de Partículas Elementares
Partículas Elementares
Modelos Teóricos
Física Nuclear/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Em] Mês de entrada:1305
[Cu] Atualização por classe:130311
[Lr] Data última revisão:
130311
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130312
[St] Status:MEDLINE


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[PMID]:23280355
[Au] Autor:Eisenberg B
[Ad] Endereço:Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois, USA.
[Ti] Título:Ionic interactions are everywhere.
[So] Source:Physiology (Bethesda);28(1):28-38, 2013 Jan.
[Is] ISSN:1548-9221
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Ionic solutions are dominated by interactions because they must be electrically neutral, but classical theory assumes no interactions. Biological solutions are rather like seawater, concentrated enough so that the diameter of ions also produces important interactions. In my view, the theory of complex fluids is needed to deal with the interacting reality of biological solutions.
[Mh] Termos MeSH primário: Interações de Partículas Elementares
Íons
Soluções
[Mh] Termos MeSH secundário: Animais
Seres Humanos
Canais Iônicos/fisiologia
Modelos Biológicos
Concentração Osmolar
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Ion Channels); 0 (Ions); 0 (Solutions)
[Em] Mês de entrada:1402
[Cu] Atualização por classe:130102
[Lr] Data última revisão:
130102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130103
[St] Status:MEDLINE
[do] DOI:10.1152/physiol.00041.2012


  9 / 128 MEDLINE  
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[PMID]:23221007
[Au] Autor:Jeckelmann E
[Ad] Endereço:Institut für Theoretische Physik, Leibniz Universität Hannover, Germany. eric.jeckelmann@itp.uni-hannover.de
[Ti] Título:Local density of states of the one-dimensional spinless fermion model.
[So] Source:J Phys Condens Matter;25(1):014002, 2013 Jan 09.
[Is] ISSN:1361-648X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We investigate the local density of states of the one-dimensional half-filled spinless fermion model with nearest-neighbour hopping t > 0 and interaction V in its Luttinger liquid phase -2t < V ≤ 2t. The bulk density of states and the local density of states in open chains are calculated over the full band width ∼4t with an energy resolution ≤0.08t using the dynamical density-matrix renormalization group (DDMRG) method. We also perform DDMRG simulations with a resolution of 0.01t around the Fermi energy to reveal the power-law behaviour D(ϵ) ∼ |ϵ - ϵ(F)|(α) predicted by the Luttinger liquid theory for bulk and boundary density of states. The exponents α are determined using a finite-size scaling analysis of DDMRG data for lattices with up to 3200 sites. The results agree with the exact exponents given by the Luttinger liquid theory combined with the Bethe Ansatz solution. The crossover from boundary to bulk density of states is analysed. We have found that boundary effects can be seen in the local density of states at all energies, even far away from the chain edges.
[Mh] Termos MeSH primário: Interações de Partículas Elementares
Partículas Elementares
Modelos Químicos
Modelos Moleculares
Teoria Quântica
[Mh] Termos MeSH secundário: Simulação por Computador
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1306
[Cu] Atualização por classe:121213
[Lr] Data última revisão:
121213
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:121211
[St] Status:MEDLINE
[do] DOI:10.1088/0953-8984/25/1/014002


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[PMID]:23215375
[Au] Autor:Ipp A; Somkuti P
[Ad] Endereço:Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10/136, A-1040 Vienna, Austria. ipp@hep.itp.tuwien.ac.at
[Ti] Título:Yoctosecond metrology through Hanbury Brown-Twiss correlations from a quark-gluon plasma.
[So] Source:Phys Rev Lett;109(19):192301, 2012 Nov 09.
[Is] ISSN:1079-7114
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Expansion dynamics at the yoctosecond time scale affect the evolution of the quark gluon plasma (QGP) created in heavy ion collisions. We show how these dynamics are accessible through Hanbury Brown-Twiss (HBT) intensity interferometry of direct photons emitted from the interior of the QGP. A detector placed close to the beam axis is particularly sensitive to early polar momentum anisotropies of the QGP. Observing a modification of the HBT signal at the proposed FoCal detector of the LHC ALICE experiment would allow us to measure the isotropization time of the plasma and could provide first experimental evidence for photon double pulses at the yoctosecond time scale.
[Mh] Termos MeSH primário: Íons Pesados
Modelos Teóricos
Gases em Plasma
[Mh] Termos MeSH secundário: Interações de Partículas Elementares
Física Nuclear/métodos
Fótons
Teoria Quântica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Plasma Gases)
[Em] Mês de entrada:1302
[Cu] Atualização por classe:121211
[Lr] Data última revisão:
121211
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:121211
[St] Status:MEDLINE



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