Vascular-Targeted Photodynamic Therapy (VTP)

International audienc

Transparence des banques et stabilité financière

This thesis tries to understand the relationship between banking disclosure and financial stability for several actors of bank's governance. Disclosure has a positive impact on financial market participant made possible by a reduction of the information premium. Regarding depositors, we decided to partially reject the hypothesis of perfect rationality by introducing the ambiguity notion. We were able to show that a negative relationship exists between ambiguity and deposit levels bath theoretically and empirically. Disclosure policies have therefore a negative impact on European total deposit empirically.Cette thèse examine l'impact de la transparence informationnelle des banques sur la stabilité financière pendant la période 1990-2013. Elle est composée de deux essais empiriques, un essai théorique, ainsi que d'une revue de la littérature. Le premier chapitre met en lumière la littérature existante, théorique et empirique, qui servira comme tremplin pour le reste de la dissertation, Le chapitre 2 teste les effets de la transparence informationnelle des banques sur les prix des swaps de crédit pendant la crise de la dette souveraine européenne, sut- la période 2010-2013. Les banques les plus transparentes sont les banques qui souffrent le moins de la volatilité des prix des swaps de crédit au moment des annonces de dégradation des notes des états. La transparence, via la gouvernance des marchés financiers participent à améliorer la stabilité financière. Le chapitre 3 teste, théoriquement, les incitations à retirer des déposants en présence d'ambiguïté et dans le cas où l'information est imparfaite. Les résultats montrent que plus leur degré de pessimisme génère une incitation supérieure à retirer leurs dépôts de l'institution dans laquelle ils ont déposés. La combinaison de l'ambiguïté et de l'asymétrie d'information ouvre la porte à de nouvelles perspectives en termes de transparence informationnelle de la part des banques en direction des déposants et participant ainsi à l'amélioration de la stabilité financière en évitant les paniques bancaires. Le chapitre 4 teste empiriquement les résultats obtenus dans le chapitre précédent. Nous testons l'attractivité, pour les déposants, des banques les plus transparentes sur la période 1990-2013 tout en prenant en considération l'ambiguïté. Les résultats confirment que l' ambiguïté a un effet négatif sur le montant des dépôts totaux des banques et que la transparence informationnelle peut activer des incitations au retrait chez les déposants

One-Dimensional Nature of InAs/InP Quantum Dashes Revealed by Scanning Tunneling Spectroscopy

We report on low-temperature cross-sectional scanning tunneling microscopy and spectroscopy on InAs­(P)/InGaAsP/InP(001) quantum dashes, embedded in a diode-laser structure. The laser active region consists of nine InAs­(P) quantum dash layers separated by the InGaAsP quaternary alloy barriers. The effect of the p-i-n junction built-in potential on the band structure has been evidenced and quantified on large-scale tunneling spectroscopic measurements across the whole active region. By comparing the tunneling current onset channels, a consistent energy shift has been measured in successive quantum dash or barrier layers, either for the ground state energy of similar-sized quantum dashes or for the conduction band edge of the barriers, corresponding to the band-bending slope. The extracted values are in good quantitative agreement with the theoretical band structure calculations, demonstrating the high sensitivity of this spectroscopic measurement to probe the electronic structure of individual nanostructures, relative to local potential variations. Furthermore, by taking advantage of the potential gradient, we compared the local density of states over successive quantum dash layers. We observed that it does not vanish while increasing energy, for any of the investigated quantum dashes, in contrast to what would be expected for discrete level zero-dimensional (0D) structures. In order to acquire further proof and fully address the open question concerning the quantum dash dimensionality nature, we focused on individual quantum dashes obtaining high-energy-resolution measurements. The study of the local density of states clearly indicates a 1D quantum-wirelike nature for these nanostructures whose electronic squared wave functions were subsequently imaged by differential conductivity mapping

Surface Chemistry Architecture of Silica Nanoparticles Determine the Efficiency of <i>in Vivo</i> Fluorescence Lymph Node Mapping

Near-infrared (NIR) imaging of the lymphatic system offers a sensitive, versatile, and accurate lymph node mapping to locate the first, potentially metastatic, draining nodes in the operating room. Many luminescent nanoprobes have received great attention in this field, and the design of nontoxic and bright nanosystems is of crucial importance. Fluorescent NIR-emitting dye doped silica nanoparticles represent valuable platforms to fulfill these scopes, providing sufficient brightness, resistance to photobleaching, and hydrophilic nontoxic materials. Here, we synthesized these highly stable core–shell nanoparticles with a programmable surface charge positioning and determined the effect of these physicochemical properties on their <i>in vivo</i> behavior. In addition, we characterized their fluorescence kinetic profile in the right axillary lymph node (RALN) mapping. We found that nanoparticles with negative charges hidden by a PEG shell are more appropriate than those with external negative charges in the mapping of lymph nodes. We also demonstrated the efficient excretion of these nanostructures by the hepatobiliary route and their nontoxicity in mice up to 3 months postinjection. These results indicate the potential future development of these fluorescent nanosystems for LN mapping

Low-Temperature Reactivity of C_2<i>n</i>+1N^– Anions with Polar Molecules

Following the recent discovery of molecular anions in the interstellar medium, we report on the kinetics of proton transfer reactions between cyanopolyynide anions C_2<i>n</i>+1N^– (<i>n</i> = 0, 1, 2) and formic acid HCOOH. The results, obtained from room temperature down to 36 K by means of uniform supersonic flows, show a surprisingly weak temperature dependence of the CN^– reaction rate, in contrast with longer chain anions. The CN^– + HCOOH reaction is further studied theoretically via a reduced dimensional quantum model that highlights a tendency of the reaction probability to decrease with temperature, in agreement with experimental data but at the opposite of conventional long-range capture theories. In return, comparing HCOOH to HC₃N as target molecules suggests that dipole–dipole interactions must play an active role in overcoming this limiting effect at low temperatures. This work provides new fundamental insights on prototypical reactions between polar anions and polar molecules along with critical data for astrochemical modeling