2,687 research outputs found

    Leishmania metacaspase: an arginine-specific peptidase.

    Get PDF
    The purpose of this chapter is to give insights into metacaspase of Leishmania protozoan parasites as arginine-specific cysteine peptidase. The physiological role of metacaspase in Leishmania is still a matter of debate, whereas its peptidase enzymatic activity has been well characterized. Among the different possible expression systems, metacaspase-deficient yeast cells (Δyca1) have been instrumental in studying the activity of Leishmania major metacaspase (LmjMCA). Here, we describe techniques for purification of LmjMCA and its activity measurement, providing a platform for further identification of LmjMCA substrates

    Temperature Dependence of Electron to Lattice Energy-Transfer in Single-Wall Carbon Nanotube Bundles

    Full text link
    The electron-phonon coupling strength in single-wall carbon nanotube (SWNT) bundles has been studied directly in the time-domain by femtosecond time-resolved photoelectron spectroscopy. We have measured the dependence of H(T_e,T_l), the rate of energy-transfer between the electronic system and the lattice as a function of electron and lattice temperatures T_e and T_l. The experiments are consistent with a T^5 dependence of H on the electron- and lattice-temperatures, respectively. The results can be related to the e-ph mass enhancement parameter lambda. The experimentally obtained value for lambda/theta_D^2, where theta_D is the Debye temperature, suggests that e-ph scattering times at the Fermi level of SWNT bundles can be exceptionally long, exceeding 1.5 ps at room temperature.Comment: 5 pages, 4 figures, submitted to the Journal of Nanoscience and Nanotechnologiy, special issue on nanotube

    Die Bedeutung der Fascia stylopharyngea bei intraoralen Blockadetechniken

    Get PDF
    Zusammenfassung: Hintergrund: Mittels transoraler Blockade des Ganglion cervicale superius des Truncus sympathicus kann bei Trigeminusneuralgien durch Ausbreitung eines Opioids bis zum N.mandibularis eine zusätzliche Schmerzreduktion erzielt werden. Das Vorhandensein der Fascia stylopharyngea senkt möglicherweise die Erfolgsrate. Durch genaue anatomische Untersuchung der Faszie wollen wir auf die Effektivität der zusätzlichen Opioidwirkung rückschließen. Material und Methode: 103 Kopfhälften wurden untersucht, die Faszie von lateral her aufgesucht. Dabei unterschieden wir 3 Gruppen: GruppeA repräsentierte vollständig ausgebildete Faszienblätter, Gruppe Bunvollständige Faszien und in GruppeC war die Faszie nicht ausgebildet. Ergebnis: Die Faszie war in 86 vollständig und in 13 Fällen unvollständig ausgebildet. Lediglich in 4 Fällen fehlte sie vollends. Schlussfolgerung: Die Faszie kann die Erfolgsquote der Schmerzreduktion bei Trigeminusneuralgie beeinflusse

    Raptor hunted by caspases.

    Get PDF

    Mitralklappenendokarditis nach türkischem Opferfest

    Get PDF
    Zusammenfassung: Erysipelothrix rhusiopathiae ist der Erreger des Schweinerotlaufs. Systemische Infektionen durch E.rhusiopathiae sind eine Rarität, jedoch häufig (zu 90%) mit Endokarditiden verbunden. Ungefähr 60% der Endokarditiden entwickeln sich auf nicht vorgeschädigten Klappen, und trotz adäquater antibiotischer Therapie benötigen etwa ein Drittel der Patienten einen Klappenersatz. Wir beschreiben den Fall einer Hausfrau, die nach Zubereitung von Fleisch für das türkische Opferfest eine Mitralklappenendokarditis durch E.rhusiopathiae entwickelt

    Bien-être et croyance en un monde juste en ex-Yougoslavie: traces laissées par les guerres et la précarité socio-économique

    Get PDF
    RÉSUMÉ En combinant la perspective du parcours de vie à la théorie du stress et selon une approche psychosociale, cette thèse montre comment les expériences individuelles et collectives de victimisation ont marqué les parcours de vie, les croyances et le bien-être d'une cohorte de jeunes adultes ayant traversé les guerres en ex-Yougoslavie. Le premier article applique des analyses de courbes de croissance à classes latentes et dégage différentes trajectoires d'exclusion entre 1990 et 2006. L'analyse de ces trajectoires met en évidence les intersections entre vies individuelles, contexte et temps socio-historique et démontre que les expériences de guerre et les périodes d'exclusion socio-économique laissent des traces sur le bien-être à long terme. Les deuxième et troisième articles montrent que la croyance en un monde juste est ébranlée suite à des expériences de précarité socio-économique et de victimisation dues à la guerre au niveau individuel et contextuel. Un effet curvilinéaire et des interactions entre les niveaux indiquent que ces relations varient en fonction de l'intensité de la victimisation au niveau contextuel. Des effets de récence sont aussi relevés. Le quatrième article démontre que l'impact négatif de la victimisation sur le bien-être est en partie expliqué par un effritement de la croyance en un monde juste. De plus, si les individus qui croient davantage en un monde juste sont plus satisfaits de leur vie, la force de ce lien varie en fonction du niveau de victimisation dans certains contextes. Cette thèse présente un modèle multiniveaux dynamique dans lequel la croyance en un monde juste n'exerce plus le rôle de ressource personnelle stable mais s'érode face à la victimisation, entraînant ainsi un bien-être moindre. Ce travail souligne l'importance d'articuler les niveaux individuels et contextuels et de considérer la dimension temporelle pour expliquer les liens entre victimisation, croyance en un monde juste et bien-être. ABSTRACT By combining a life course perspective to stress theory and according to a psychosocial approach, this thesis shows how individual and collective victimisation experiences marked the life course, beliefs and well-being of a cohort of young adults who lived through the wars in former Yugoslavia. In the first article, latent class growth analyses were applied to identify different exclusion trajectories between 1990 and 2006. The analysis of these trajectories highlighted the intersections between individual lives, socio-historical context and time and demonstrated that experiences of war and socio-economic exclusion leave traces on well-being in the long term. The second and third articles showed that the belief in a just world was shattered due to socio-economic precariousness and war victimisation at individual and contextual levels. A curvilinear effect and cross-level interactions indicated that these relations varied according to the intensity of victimisation at the contextual level. Time effects were also noted. The fourth article showed that the negative impact of victimisation on well-being was partly explained by an erosion of the belief in a just world. Furthermore, if high believers were more satisfied with their lives, the strength of this relation varied depending on the level of victimisation in particular contexts. This thesis presents a multilevel dynamic model in which the belief in a just world no longer exercises the role of a stable personal resource but erodes in the face of victimisation, leading to a lower well-being. This work stresses the importance of articulating individual and contextual levels as well as considering the temporal dimension to explain the links between victimisation, belief in a just world and well-being

    Theoretical analysis of the electronic structure of the stable and metastable c(2x2) phases of Na on Al(001): Comparison with angle-resolved ultra-violet photoemission spectra

    Full text link
    Using Kohn-Sham wave functions and their energy levels obtained by density-functional-theory total-energy calculations, the electronic structure of the two c(2x2) phases of Na on Al(001) are analysed; namely, the metastable hollow-site structure formed when adsorption takes place at low temperature, and the stable substitutional structure appearing when the substrate is heated thereafter above ca. 180K or when adsorption takes place at room temperature from the beginning. The experimentally obtained two-dimensional band structures of the surface states or resonances are well reproduced by the calculations. With the help of charge density maps it is found that in both phases, two pronounced bands appear as the result of a characteristic coupling between the valence-state band of a free c(2x2)-Na monolayer and the surface-state/resonance band of the Al surfaces; that is, the clean (001) surface for the metastable phase and the unstable, reconstructed "vacancy" structure for the stable phase. The higher-lying band, being Na-derived, remains metallic for the unstable phase, whereas it lies completely above the Fermi level for the stable phase, leading to the formation of a surface-state/resonance band-structure resembling the bulk band-structure of an ionic crystal.Comment: 11 pages, 11 postscript figures, published in Phys. Rev. B 57, 15251 (1998). Other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm

    A simple approach for describing metal-supported cyclohexaphenylene dehydrogenation: Hybrid classical/DFT metadynamics simulations

    Get PDF
    The mechanisms for the dehydrogenation reaction of cyclohexaphenylene at a copper surface are investigated with the help of density functional theory and metadynamics. Our results represent a showcase for an approach that describes the surface using many-body classical potentials and molecule-surface interactions with a van der Waals model. Starting from the experimental observation that dispersion-assisted mechanisms are at least as important as catalytic processes for the description of the reaction, we fully describe the former, we identify intermediate states and estimate the free energy barriers that characterize the reactio
    corecore