Picometer resolution profilometer for hollow-core fiber surface roughness characterization

We build a picometer-sensitivity optical surface-profiler based on polarization-interferometry. The profilometer is design to measure surface roughness profiles of HCPCF. Two HCPCF categories with different fabrication processes were characterized. We observe that for HCPCFs fabricated the new process exhibit a reduction of rms core-surface roughness rms by a factor of close to 3 relative to the surface capillary wave thermodynamic limit, and thus explaining the record loss achieved in the VIS-UV range achieved with these fibers

Iterative sorting reveals CD133+ and CD133- melanoma cells as phenotypically distinct populations

Background: The heterogeneity and tumourigenicity of metastatic melanoma is attributed to a cancer stem cell model, with CD133 considered to be a cancer stem cell marker in melanoma as well as other tumours, but its role has remained controversial. Methods: We iteratively sorted CD133+ and CD133- cells from 3 metastatic melanoma cell lines, and observed tumourigenicity and phenotypic characteristics over 7 generations of serial xeno-transplantation in NOD/SCID mice. Results: We demonstrate that iterative sorting is required to make highly pure populations of CD133+ and CD133- cells from metastatic melanoma, and that these two populations have distinct characteristics not related to the cancer stem cell phenotype. In vitro, gene set enrichment analysis indicated CD133+ cells were related to a proliferative phenotype, whereas CD133- cells were of an invasive phenotype. However, in vivo, serial transplantation of CD133+ and CD133- tumours over 7 generations showed that both populations were equally able to initiate and propagate tumours. Despite this, both populations remained phenotypically distinct, with CD133- cells only able to express CD133 in vivo and not in vitro. Loss of CD133 from the surface of a CD133+ cell was observed in vitro and in vivo, however CD133- cells derived from CD133+ retained the CD133+ phenotype, even in the presence of signals from the tumour microenvironment. Conclusion: We show for the first time the necessity of iterative sorting to isolate pure marker-positive and marker-negative populations for comparative studies, and present evidence that despite CD133+ and CD133- cells being equally tumourigenic, they display distinct phenotypic differences, suggesting CD133 may define a distinct lineage in melanoma

Caractérisation et contrôle de surface pour une nouvelle génération de fibres creuses

This PhD thesis focuses on the loss challenges induced by the presence of surface roughness within hollow-core photonic crystal fibers (HCPCF). This phenomenon located at the core/cladding interface currently limits the performance of these hollow-core fibers both at short ultraviolet wavelengths and at the infrared, the reference spectral range for optical telecommunications. In this context, my thesis work was divided into two complementary research strategies. A first axis aimed to design and produce HCPCF fibers with reduced surface roughness by implementing innovative manufacturing techniques. A second axis focused on the characterization of this surface roughness and the diffusion induced within the HCPCF fibers by the complete construction of an optical profilometer with picometric resolution and a resonant optical cavity. The results obtained then made it possible to improve the surface quality by a factor of 3 by applying a “shear” principle to the core/clad interface which resulted in a new state-of-the-art of loss in inhibited coupling HCPCF fibers at the visible and ultraviolet spectral range: 50 dB/km at 290 nm, 9.7 dB/km at 369 nm, 5.0 dB/km at 480 nm, 0.9 dB/km at 558 nm and 1.8 dB/km at 719 nm. Also, by implementing a second original fabrication technique called “opto-thermal”, it was demonstrated that the dynamics of the surface capillary waves generated can be controlled, making possible for the first time to structure the associated surface profile. Finally, all of these advances demonstrate the realization of a new generation of hollow-core fibers.Cette thèse de doctorat se focalise sur la problématique des pertes induites par la présence d’une rugosité de surface au sein des fibres optiques à cœur creux (HCPCF). Ce phénomène localisé à l’interface cœur/gaine a pour conséquence de limiter actuellement les performances de ces fibres creuses aussi bien aux courtes longueurs d’onde de l’ultraviolet qu’à l’infrarouge, domaine spectral de référence des télécommunications optiques. Dans ce contexte, mes travaux de thèse se sont déclinés en deux voies de recherche complémentaires. Un premier axe a eu pour objectif de concevoir et réaliser des fibres HCPCF à rugosité de surface réduite par l’implémentation de techniques de fabrication innovantes. Un second axe s’est lui focalisé sur la caractérisation de cette rugosité de surface et de la diffusion induite au sein des fibres HCPCF par la construction complète d’un profilomètre optique de résolution picométrique et d’une cavité optique résonante. Les résultats obtenus ont alors permis d’améliorer la qualité de surface d’un facteur 3 en appliquant un principe de « cisaillement » à l’interface cœur/gaine qui se sont traduits par un nouvel état de l’art des pertes des fibres HCPCF à couplage inhibé dans la gamme spectrale du visible et de l’ultraviolet : 50 dB/km à 290 nm, 9,7 dB/km à 369 nm, 5,0 dB/km à 480 nm, 0,9 dB/km à 558 nm et 1,8 dB/km à 719 nm. Aussi, en implémentant une seconde technique originale de fabrication dite « opto-thermique », il a été démontré qu’on pouvait agir sur la dynamique des ondes capillaires de surface générée permettant pour la première fois de venir structurer le profil de surface associé. Finalement, l’ensemble de ces avancées témoignent de la réalisation d’une nouvelle génération de fibres creuses

PowerPoint Slides for: New Onset Hypertension Linked to Generic Cyclosporine Substitution in Post-Renal Transplant Patient

This is case report and review of the literature focused on generic substitutions of cyclosporine and its consequences. The pharmacokinetics and pharmacodynamics of the generic substitutions are clear different than the parent compound Sandimmune and can lead to different outcomes, as was the case in this report. A detailed accounting of the patients history led to the discovery of the problem and sorting back to a the branded drug supported the hypothesis