24 research outputs found
REHABILITACIÓN CON IMPLANTES EN EL SECTOR ANTEROSUPERIOR
No full textSebban, Samuel; director de proyecto: Jiménez Vilariño, Rosa María2021-2022Grado en OdontologíaFacultad de Odontologí
Automating the determination of wave speed using the pu-loop method
No full textThe PU-loop (pressure-velocity loop) is a method for determining wave speed and relies on the linear relationship between the pressure and velocity in the absence of reflected waves. This linearity of the PU-loop during early systole, which is directly related to wave speed, has always been established by eye. This paper presents a new technique that establishes this linearity and thus determining wave speed online. Pressure and flow were measured in the ascending aorta of 11 anesthetised dogs. The slope of the PU-loop, indicating wave speed was determined by eye and by using the new technique. The difference between the slopes of the two methods is in the order of 3%. The new technique is convenient and allows for the online assessment of wave speed, which could be used as a bedside tool for the assessment of arterial compliance
The conformation of tetrafluorinated methyl galactoside anomers: crystallographic and NMR studies
No full textThe first single-crystal X-ray diffraction study of tetrafluorinated monosaccharide derivatives is presented.Both a- and b-methyl 2,3-dideoxy-2,2,3,3-tetrafluoro-D-galactopyranoside anomers adopt the4C1 conformation. The values for the C1–O1 and C1–O5 bond lengths and the O5–C1–O1–CH3 dihedralangles are in line with what can be expected from the anomeric and exo-anomeric effects. The chair conformationsare slightly distorted, presumably due to repulsion between 1,3-diaxial C–O and C–F bonds.The asymmetric unit of both compounds contains up to three independent molecules, which differ inthe conformation of the hydroxymethyl group (including in one case a ‘forbidden’ gg rotamer). Themolecular packing of the b-anomer shows a clear segregation between fluorinated and hydrophilicdomains, while for the a-anomer the regions of fluorine segregation are broken by interleafing of OMegroups. There is one close OH? ? ?F contact, which is likely to arise from the crystal packing. NMR studiesshow that the two anomers also adopt a 4C1 conformation in solution (D2O, CDCl3)
The enantioselective synthesis of dideoxy-tetrafluorinated hexoses
No full textCarbohydrates typically have low affinities to protein binding sites, and the development of carbohydrate mimetics with improved binding is therefore of interest. Tetrafluorination of monosaccharides is one of the strategies currently under investigation for that purpose. The synthesis of the required tetrafluorinated monosaccharides is achieved by a fluorinated building block approach. The enantioselective synthesis of tetrafluorinated hexose derivatives is described here, both in the pyranose and furanose form. In particular, the optimization of the enantioselective synthesis of the previously reported 2,3-dideoxy-2,2,3,3-tetrafluoro-D-threo-hexopyranose 3, 2,3-dideoxy-2,2,3,3-tetrafluoro-D-threo-hexofuranose 4, and 2,3-dideoxy-2,2,3,3-tetrafluoro-D-erythro-hexopyranose 5 is described, as well as the synthesis of two novel sugar derivatives, 3,4-dideoxy-3,3,4,4-tetrafluoro-D-threo-hexopyranose 6 and 3,4-dideoxy-3,3,4,4-tetrafluoro-D-erythro-hexopyranose 7. The key step of all syntheses is a perfluoroalkyl lithium mediated C–C bond formation, either intramolecular or intermolecular, and proceeds in good to excellent yields. NMR and X-ray crystallographic analysis of the tetrafluorinated methyl pyranoside derivatives confirms their 4C1 conformation
Wavefront improvement in an injection-seeded soft x-ray laser based on a solid-target plasma amplifier
Get PDFInternational audienceThe wavefront of an injection-seeded soft x-ray laser beam generated by amplification of high-harmonic pulses in a lambda = 18.9 nm molybdenum plasma amplifier was measured by a Hartmann wavefront sensor with an accuracy of lambda/32 root mean square (rms). A significant improvement in wavefront aberrations of 0.51 +/- 0.03 lambda rms to 0.23 +/- 0.01 lambda rms was observed as a function of plasma column length. The variation of wavefront characteristic as a function time delay between the injection of the seed and peak of soft x-ray amplifier pump was studied. The measurements were used to reconstruct the soft x-ray source and confirm its high peak brightness. (C) 2013 Optical Society of Americ
Efficient access to fluorinated homoallylic alcohols through an indium promoted fluoroallylation reaction
No full textInternational audienc
ChemInform Abstract: Efficient Access to Fluorinated Homoallylic Alcohols Through an Indium Promoted Fluoroallylation Reaction.
No full textFemtosecond soft x-ray lasing in dense collisionaly-pumped plasma
No full textInternational audienceWe report the first experimental measurement of a strong pulse shortening of a seeded plasma-based soft x-ray laser at high electron densities. As a consequence of the gain gating caused by subsequent collisional ionization, the duration drops from 1.4 ps to an unprecedented value of 520 fs RMS when the electron density increases from 4 to 7.6×1019cm-3. These measurements, performed with an original single-shot method, are in good agreement with results from 3D Maxwell-Bloch simulations. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DO
Toward the Synthesis of Fluorinated Analogues of HCV NS3/4A Serine Protease Inhibitors Using Methyl α‑Amino-β-fluoro-β-vinylcyclopropanecarboxylate as Key Intermediate
No full textSynthesis
of fluorocyclopropyl building blocks, which constitute
the core of various therapeutic agents against the hepatitis C virus,
is described. The relevant methyl α-amino-β-fluoro-β-vinylcyclopropanecarboxylate
has been used as a key intermediate for the total synthesis of a fluorinated
analogue of Simeprevir (TMC 435), a HCV NS3/4A protease inhibitor
