Estudios de acoplamiento molecular de nuevos análogos de quinolonas a la ADN girasa de Escherichia coli

Indexación: Scopus.Chemicals and CAS Registry Numbers: amino acid, 65072-01-7; ciprofloxacin, 85721-33-1; DNA topoisomerase (ATP hydrolysing); gatifloxacin, 112811-59-3, 180200-66-2; levofloxacin, 100986-85-4, 138199-71-0; lomefloxacin, 98079-51-7; moxifloxacin, 151096-09-2; nalidixic acid, 389-08-2; oxolinic acid, 14698-29-4; pipemidic acid, 51940-44-4; rufloxacin, 101363-10-4; sitafloxacin, 127254-12-0, 163253-35-8Context: Bacterial resistance to antibiotics is the inevitable consequence of the use of antimicrobial agents. Thus, quinolones are an important class of antibacterials; these agents generally consist of a 1-subtituted-1,4-dihydro-4-oxopyridine-3-carboxylic acid moiety combined with an aromatic or heteroaromatic ring fused at the 5- and 6-position. Aims: To determine the binding of quinolones to DNA gyrase of Escherichia coli. Methods: An analysis was performed using an in silico approach to determine, by docking calculations and energy descriptors, the conformer of 4‐oxo‐1,4‐dihydroquinoline skeleton that forms the most stable complex with DNA gyrase of E. coli. Results: The complex shows that the pose of the quinolones coincides with the amino acid residues Asp87, Thr88, Arg91 and Met92, which is expected to be critical in the binding of quinolones to DNA gyrase of E. coli. A series of quinolones were computationally designed, and the interactions between the quinolones and the amino acid residues of the DNA gyrase were calculated. Conclusions: Among the designed compounds, compounds 105 and 115 exhibit higher binding energy values and interact with amino acids Asp87, Thr88, Arg91 and Met92. © 2018 Journal of Pharmacy & Pharmacognosy Research.http://jppres.com/jppres/pdf/vol6/jppres18.368_6.5.386.pd

Scalar-tensor theory with EGB term from Einstein Chern-Simons gravity

It is shown that the compactification a la Randall Sundrum of the so called, five dimensional Einstein Chern Simons action gravity leads to an action for a four dimensional scalar tensor gravity that includes a Gauss Bonnet term, which belongs to a particular case of the action of the Horndeski theory. The five dimensional action includes new gravitational degrees of freedom that were introduced requiring that the action be invariant under symmetries greater than the usual Poincare or (A)dS symmetries, namely the so called generalized Poincare algebras B5.Comment: To be published in Nucl. Phys.

Higher dimensional gravity invariant under the Poincare group

It is shown that the Stelle-West Grignani-Nardelli-formalism allows, both when odd dimensions and when even dimensions are considered, constructing actions for higher dimensional gravity invariant under local Lorentz rotations and under local Poincar\`{e} translations. It is also proved that such actions have the same coefficients as those obtained by Troncoso and Zanelli in ref. Class. Quantum Grav. 17 (2000) 4451.Comment: 7 pages, Latex, accepted in Phys. Rev.

Weak boson production measured in PbPb and pp collisions by CMS

The unprecedented center-of-mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions at extreme temperatures and very low parton momentum fractions. Electroweak boson production is an important benchmark process at hadron colliders. Precise measurements of Z production in heavy-ion collisions can help to constrain nuclear PDFs as well as serve as a standard candle of the initial state in PbPb collisions at the LHC energies. The inclusive and differential measurements of the Z boson yield in the muon decay channel will be presented, establishing that no modification is observed with respect to next-to-leading order pQCD calculations, scaled by the number of incoherent nucleon-nucleon collisions. The status of the Z measurement in the electron decay channel, as well as the first observation of W \rightarrow \mu {\nu} in heavy ion collisions will be given. The heavy-ion results will be presented in the context of those obtained in pp collisions with the CMS detector.Comment: Quark Matter 2011 conference proceeding

Aporte de la Melisopalinología al conocimiento de la flora melífera de un sector de la Provincia Fitogeográfica Chaqueña, Argentina

Melissopalynological contribution to the knowledge of the honey flora in a sector of the Phytogeographic Chaquenian Province, Argentina. The honey flora of a sector of the Occidental y OrientalChaco phytogeographic province, Argentina, was studied. Availability of plant flowering, considering the botanical origin of pollen grains contained in honey samples was investigated. Plant specimens and honey samples were collected in 20 apiaries during spring and summer of years 2004 to 2007. The flowering period in the studied region is larger than in other Argentine an regions, extending almost the entire year. Field records revealed the presence of 282 plants species belonging to 65 Angiosperms families being Fabaceae and Asteraceae the most well represented. Two flowering peaks were detected, one between September and December, and the other from February until late March. The first peak of flowering involves a larger number of plant species than the second. Major flowering contribution was produced bynative species; woody plants are dominant in spring and herbaceous ones in summer. Although 118 pollen types were identified in the honey samples, the main nectar sources came from a few plants belonging to Asteraceae, Anacardiaceae, Arecaceae, Fabaceae, Rhamnaceae and Zygophyllaceae.La composición y la oferta de floración de la flora melífera de los dos Distritos de la provinciafitogeográfica Chaqueña, fue estudiada a partir del seguimiento de la floración y del análisis de mielesproducidas en diferentes momentos de la temporada apícola. La recolección de ejemplares y de muestrasde miel fue realizada durante los años 2004 al 2007 en 20 apiarios. En la región estudiada la oferta defloración es más extensa que en otras regiones argentinas, extendiéndose durante la mayor parte del año.A partir de los registros a campo se relevaron 282 especies pertenecientes a 65 familias de Angiospermas,siendo Fabaceae y Asteraceae las más representadas. Se detectaron dos picos de floración, uno entreseptiembre y diciembre, y otro desde febrero hasta fines de marzo. El primer pico de floración es másintenso que el segundo. La principal oferta de floración es producida por especies nativas, siendo lasleñosas más comunes en primavera y las herbáceas en verano. De los 118 tipos de polen identificados enlas mieles, sólo unos pocos representan fuentes nectaríferas importantes, ellos pertenecen a las siguientesfamilias: Asteraceae, Anacardiaceae, Arecaceae, Fabaceae, Rhamnaceae y Zygophyllaceae

The Cauchy problem of scalar-tensor theories of gravity

The 3+1 formulation of scalar-tensor theories of gravity (STT) is obtained in the physical (Jordan) frame departing from the 4+0 covariant field equations. Contrary to the common belief (folklore), the new system of ADM-like equations shows that the Cauchy problem of STT is well formulated (in the sense that the whole system of evolution equations is of first order in the time-derivative). This is the first step towards a full first order (in time and space) formulation from which a subsequent hyperbolicity analysis (a well-posedness determination) can be performed. Several gauge (lapse and shift) conditions are considered and implemented for STT. In particular, a generalization of the harmonic gauge for STT allows us to prove the well posedness of the STT using a second order analysis which is very similar to the one used in general relativity. Some spacetimes of astrophysical and cosmological interest are considered as specific applications. Several appendices complement the ideas of the main part of the paper.Comment: 29 pages Revtex; typos corrected; references added and updated; a shorter version of this paper was published in Classical and Quantum Gravit

Índice mitótico e viabilidade celular de calos embriogênicos de murici-pequeno.

Byrsonima intermedia é uma espécie lenhosa e medicinal de ocorrência nos Cerrados brasileiros. O objetivo desta pesquisa foi determinar o padrão de divisão e viabilidade de células com características embriogênicas. Segmentos foliares foram inoculados em meio de cultura MS suplementada com 1,0 mg L-1 de 2,4-D. As repicagens foram efetuadas por três vezes, todas aos sessenta dias, resultando em três subcultivos. Avaliou-se a viabilidade celular e o índice mitótico de células com características embriogênicas, no segundo subcultivo. No segundo subcultivo, aos 20 e 40 dias, ocorrem os maiores índices de divisão celular. Até os 80 dias de incubação dos calos, ocorre a maior porcentagem de células viáveis com características embriogênicas

Induced scalarization in boson stars and scalar gravitational radiation

The dynamical evolution of boson stars in scalar-tensor theories of gravity is considered in the physical (Jordan) frame. We focus on the study of spontaneous and induced scalarization, for which we take as initial data configurations on the well-known S-branch of a single boson star in general relativity. We show that during the scalarization process a strong emission of scalar radiation occurs. The new stable configurations (S-branch) of a single boson star within a particular scalar-tensor theory are also presented.Comment: 18 pages, 11 figures. Minor changes to match the published versio

Supergravity with cosmological constant and the AdS group

It is shown that the supersymmetric extension of the Stelle-West formalism permits the construction of an action for $(3+1)$-dimensional N=1 supergravity with cosmological constant genuinely invariant under the $OSp(4/1).$ Since the action is invariant under the supersymmetric extension of the $AdS$ group, the supersymmetry algebra closes off shell without the need for auxiliary fields. The limit case $m\to 0$, i.e.$(3+1)$ -dimensional N=1 supergravity invariant under the Poincar\'{e} supergroup is also discussed.Comment: 10 page