23,982 research outputs found
A comparative QM/MM study of the reaction mechanism of the Hepatitis C virus NS3/NS4A protease with the three main natural substrates NS5A/5B, NS4B/5A and NS4A/4B
No full textThe reaction mechanism of the NS3/NS4A protease with the NS4B/5A and NS4A/4B natural substrates has been investigated using the QM/MM (quantum mechanics/molecular mechanics) approach, and some calculations have been performed on the reaction with the NS5A/5B natural substrate. This study widely extends a previous contribution of our group on the reaction mechanism with the NS5A/5B substrate, the main goal here being to understand the differences found between the reaction mechanism of each natural substrate and the role played by the enzymatic residues in the catalytic cycle. This knowledge will ultimately help in developing new NS3/NS4A protease inhibitors. The two first steps of the mechanism have been considered: Acylation and breaking of the peptide bond, with emphasis on the former one (rate limiting process). Energy and free energy profiles for both steps have been calculated at the AM1/MM level and corrected by means of MP2 ab initio calculations, being evident the importance of correlation energy. Acylation is the rate limiting step in all cases and occurs through a tetracoordinated intermediate, as previously suggested for other serine proteases. Specificities in the NS4B/5A mechanism can be attributed to the presence of a Proline residue in the substrate P2 position. The analysis of structures and energies confirm the importance of the oxyanion hole in the electrostatic stabilization of the tetracoordinated intermediate. Finally, the role of other residues, e.g., Arg-155 and Asp-79, has been explained, and the viability of Arg-155 mutants and its resistance to some protease inhibitors has been understood thanks to virtual mutation studies. © the Owner Societies
Marriage record of Gonzalez, Alejandro and Gobantes, Elvira
No full textMarriage license for Alejandro Gonzalez and Elvira Gobantes. Jose Lopez was the officiant
ALDEBARAN: A "SYSTEM" DEMONSTRATOR PROJECT FOR NEW GENERATIONS OF SPACE TRANSPORTATION, NOW ENTERING IN THE PHASE A.
No full textAldebaran is the name chosen for a "system" demonstrator project which paves the way for one or more
next-generation launch vehicle targets.
The proposed demonstrator comes at a time when it is planned to operate existing European launch
vehicles (ARIANE 5, Soyuz, VEGA) until around 2025, with in parallel preparations activities for the
development of a new generation launcher. The project is aiming at developing a flight demonstrator by
focusing certain activities involved in the preparation of future launch vehicles. The first launch may take
place around 2015. It would represent a major contribution to the development of a new-generation
launch vehicle.
Several Aldebaran concepts have already been analysed in the “phase 0” during 2008. A selection process
have been applied taking into account the benefit of the proposed new technologies for the future launch
systems, but also the interest of the partners for instance by taking advantage of research activities already
foreseen. An other important selection criteria was the global development cost until the first
technological flight. The result of this “phase 0” selection process will be explained.
Three concepts have been retained for the “phase A”:
- An airborne solution launched from a military aircraft which will allow to build a dual stages
expendable “system” demonstrator, involving the main technological innovations in the frame of the solid
propulsion (first stage with new propellants), the liquid propulsion (upper stage with methane), the
structures and materials, the avionics and more globally: the “system” activities. The work foreseen in
phase A will not only focus on general studies for system and propulsion, but it will also concentrate on
some first technological sub-system demonstration tests.
- As a first alternative, an airdropped concept, launched from a cargo aircraft, is kept. It will mainly
be studied regarding safety and operational aspects in addition with the “extraction” phase when the
demonstrator is airdropped from the cargo bay, and has to be ignited at a safe distance from the aircraft.
The technologies involved in this concept are identical to the previous ones.
- As a second alternative, a “more conventional” vertical ground lift-off type of expendable solution
is retained. The idea is to push as far as possible the technological choices for a “very low cost” launch
system, the propellant choices remaining “open”. As for the airborne solution, general studies and subsystem
demonstration tests will be addressed during the phase A.
The paper will present the result of the “phase 0” concepts selection process held in 2008. And it will
show some of the first technological choices and demonstrations envisaged for the phase A of Aldebaran
The Iberian lynx needs networks of large reserves
No full textRodriguez Alejandro. The Iberian lynx needs networks of large reserves. In: Ecologia mediterranea, tome 28 n°2, 2002. p. 101
A new colony of critically endangered Northern Bald Ibises has been discovered in an Al Badia (desertic steppe) area of central Syria
No full textRodriguez Alejandro. A new colony of critically endangered Northern Bald Ibises has been discovered in an Al Badia (desertic steppe) area of central Syria. In: Ecologia mediterranea, tome 28 n°2, 2002. p. 101
Risk of Iberian lynx mortality under different hunting regimes: implications for the selection of reintroduction sites
No full textRodriguez Alejandro. Risk of Iberian lynx mortality under different hunting regimes: implications for the selection of reintroduction sites. In: Ecologia mediterranea, tome 30 n°2, 2004. pp. 242-243
Conferencia: "Medievo y Cine". D. Jorge Alejandro Eiroa Rodriguez. Facultad de Derecho.
No full textConferencia: "Medievo y Cine". D. Jorge Alejandro Eiroa Rodriguez. Facultad de Derecho
Alejandro Gonzalez Inarritu backstage at the 2014 (87th) Academy Awards ceremony
No full textAlejandro Gonzalez Inarritu, winner, Directing (BIRDMAN OR (THE UNEXPECTED VIRTUE OF IGNORANCE)) backstage at the 2014 (87th) Academy Awards ceremony. Color tiff
Protección de los artistas visuales a través del droit de suite o derecho de participación : acercamiento a su aplicación en Argentina
No full textFil: Rodriguez Fudickar, Alejandro. Universidad de San Andrés. Departamento de Derecho; Argentina
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