2,003 research outputs found

    Photochemical studies of cis-[Ru(bpy)2(4-bzpy)(CO)](PF6)2 and cis-[Ru(bpy)2(4-bzpy)(Cl)](PF6): Blue light-induced nucleobase binding.

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    The ruthenium(II) compounds cis-[Ru(bpy)2(4-bzpy)(CO)](PF6)2 (I) and cis-[Ru(bpy)2(4-bzpy)(Cl)](PF6) (II) (4-bzpy=4-benzoylpyridine, bpy=2,2'-bipyridine) were synthesized and characterized by spectroscopic and electrochemical techniques. The crystal structure of II was determined by X-ray diffraction. The photochemical behavior of I in aqueous solution shows that irradiation with ultraviolet light (365nm) releases both CO and 4-bzpy leading to the formation of the cis-[Ru(bpy)2(H2O)2]2+ ion as identified by NMR and electronic spectroscopy. Carbon monoxide release was confirmed with the myoglobin method and by gas chromatographic analysis of the headspace. CO release was not observed when aqueous I was irradiated with blue light (453nm). Changes in the electronic and 1H NMR spectra indicate that I undergoes photoaquation of 4-bzpy to form cis-[Ru(bpy)2(CO)(H2O)]2+. Blue light irradiation of aqueous II released the coordinated 4-bzpy to give the cis-[Ru(bpy)2(H2O)(Cl)]2+ ion. When the latter reaction was carried out in the presence of the nucleobase guanine, Ru-guanine adducts were formed, indicating that the metal containing photoproduct may also participate in biologically relevant reactions. The photochemical behavior of I indicates that it can release either CO or 4-bzpy depending on the wavelength chosen, a feature that may have therapeutic application

    Avaliação e tratamento do doente com acne - Parte II: tratamento tópico, sistémico e cirúrgico, tratamento da acne na grávida, algoritmo terapêutico

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    O Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte II discute-se a abordagem terapêutica – tópica e sistémica – em cada forma clínica de acne, dando particular ênfase aos retinóides e aos antimicrobianos, e salientam-se as estratégias a adoptar para limitar a crescente resistência bacteriana aos antibióticos. Referem-se as indicações específicas para terapêutica hormonal e analisam-se as particularidades do tratamento da acne na grávida e lactante. Descrevem-se algumas técnicas para correcção das cicatrizes da acne. Por último, publica-se um algoritmo que pretende ilustrar a classificação da acne e definir, para cada tipo clínico, a abordagem terapêutica consensualmente recomendada

    Avaliação e tratamento do doente com acne – Parte I: Epidemiologia, etiopatogenia, clínica, classificação, impacto psicossocial, mitos e realidades, diagnóstico diferencial e estudos complementares

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    O Portuguese Acne Advisory Board (PAAB), grupo de dermatologistas portugueses que, à semelhança de grupos congéneres internacionais, tem dedicado particular atenção à definição de linhas de orientação para o tratamento da acne, pretende que o presente documento constitua uma ferramenta útil na abordagem dos doentes com esta patologia. Elaborou-se um dossier, para educação médica contínua, subdividido em 2 partes: Parte I – etiopatogenia e clínica; Parte II – abordagem terapêutica. Nesta Parte I, revêem-se os principais aspectos da clínica e da fisiopatogenia da acne à luz dos conhecimentos actuais. Discute-se a importância do impacto psicológico e social desta entidade e analisam-se os principais mitos e realidades com ela relacionados. Descrevem-se, sucintamente, as patologias mais relevantes no diagnóstico diferencial das lesões de acne. Enumeram-se as indicações para estudo hormonal, bem como os exames a efectuar nos doentes com esta patologia. The Portuguese Acne Advisory Board (PAAB), a group of Portuguese dermatologists with a special interest in acne, develop, as other international groups in this field, consensus recommendations for the treatment of acne. Overall, the goal is to provide a practice guideline to all physicians dealing with this entity. The continuing medical education dossier was divided in two parts: Part I – etiopathogeny and clinical features; Part II – therapy. This Part I reviews acne pathophysiology, clinical aspects, psychological and social impact and several myths surrounding this disease. Some other entities relevant for the differential diagnosis are described. The need of hormonal evaluation is also discusse

    Stationary Black Holes: Uniqueness and Beyond

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    The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.Comment: Major update of the original version by Markus Heusler from 1998. Piotr T. Chru\'sciel and Jo\~ao Lopes Costa succeeded to this review's authorship. Significantly restructured and updated all sections; changes are too numerous to be usefully described here. The number of references increased from 186 to 32

    How portuguese and american teachers plan for literacy instruction

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    This study explored American and Portuguese elementary teachers' preferences in planning for literacy instruction using the Language Arts Activity Grid (LAAG; Cunningham, Zibulsky, Stanovich, & Stanovich, 2009), on which teachers described their preferred instructional activities for a hypothetical 2-h language arts block. Portuguese teachers (N = 186) completed Portuguese versions of a background questionnaire and LAAG electronically, in Survey Monkey; American teachers (N = 102) completed identical English measures using paper and pencil. Results showed that teachers in both groups usually addressed comprehension and reading fluency on their LAAGs and that they also allocated the most time to these two areas. However, American teachers were more likely to include teacher-directed fluency activities, whereas Portuguese teachers were more likely to include fluency activities that were not teacher directed. Significantly more American than Portuguese teachers addressed phonics in their planning, whereas significantly more Portuguese than American teachers addressed writing processes such as revision. Both groups of educators demonstrated large variability in planning, with many teachers omitting important components of literacy identified by researchers, for writing as well as reading. The study highlights the importance of providing teachers with comprehensive, research-based core literacy curricula as well as professional development on key components of literacy. Study findings also suggest significant relationships between orthographic transparency and teachers' instructional planning.This research was supported by a 2-year grant from the Foundation Francisco Manuel dos Santos in Portugal as well as by a Connecticut State University research grant in the U.S.A. We would like to express our sincere gratitude to these funding agencies as well as to the teachers and school districts who participated in the study and sent messages of interest about our research. In addition, warm thanks to our research assistants for their help with data collection, coding, and analysis, and to Anne Cunningham for providing us with inspiration as well as guidance in this work.info:eu-repo/semantics/publishedVersio

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for the standard model Higgs boson at LEP

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    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

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    A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector
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