La stratégie la plus utilisée aujourd'hui pour la conception de nouveaux matériaux luminescents est basée sur des méthodes d'essais-erreurs. Cependant, ces méthodes peuvent souvent entraîner une consommation d'argent et de temps. En ce sens, un modèle théorique agissant comme un outil prédictif peut servir comme une stratégie alternative. De tels modèles sont également étudiés et utilisés par des scientifiques du monde entier, mais ils sont pour la plupart difficiles à utiliser. Dans ce travail, deux modèles semi-empiriques conviviaux et faciles à utiliser ont été proposés pour la conception de luminophores intégrés dans le développement de technologies importantes, en particulier dans les éclairages à base de LED et les cellules solaires. Ces modèles sont: 1) le modèle de facteur environnemental (EF) basé sur la théorie diélectrique de la liaison chimique proposée par Philips et 2) le modèle de transfert de charge métal-métal (MMCT) utilisées pour trouver des relations entre les propriétés structurelles d'un matériau et sa luminescence. Le modèle EF a été appliqué à la famille des composés AIBIIPO4 (AI = cation monovalent, BII = cation divalent) dopés à Eu2+. Il était capable d'estimer l'énergie du bord d'excitation et d'identifier les sites de dopage à ± 1000 cm-1. Il peut donc être utilisé pour la conception de nouveaux luminophores appartenant à cette famille. Dans la deuxième partie, les deux modèles ont été utilisés pour identifier la nature de la luminescence dans les oxydes dopés à Bi3+. A cet effet, une méthode combinant les modèles motionnés avec les valeurs de Stokes shift a été trouvé fiable. En outre, la a été jugée utile pour expliquer la modification des propriétés luminescentes de YVO4:Bi3+ sous haute pression. Dans la troisième partie, les deux modèles ont été utilisés pour explorer la luminescence des oxydes dopés à Sb3+ par analogie avec Bi3+. Cependant, les résultats n'étaient pas assez bons pour identifier la nature de la luminescence dans ces matériaux. La raison pourrait être liée à la position décentrée du dopant (Sb3+). / The most used strategy for the design of new luminescent materials today is based on trial-error methods. However, these methods may often result in consummation of money and time. In this sense, a theoretical model acting as a predictive tool can serve as an alternative strategy. Such models are also studied and used by scientists around the world but they are mostly difficult to use. In this work, two friendly and easy to use semi-empirical theoretical models were proposed as a criterion for designing phosphors integrated in the development of important technologies especially in LED-based lightings and solar cells. These models are: 1) the environmental factor model (EF) based on the dielectric theory of chemical bonding proposed by Philips and 2) the metal to metal charge transfer (MMCT) model by Boutinaud that were both used for the purpose of finding relationships between the structural properties of a material and its luminescence. The EF model was applied on the family of AIBIIPO4 (AI= monovalent cation, BII= divalent cation) compounds doped with Eu2+. It was able to estimate the excitation edge energy and to identify the doping sites within uncertainty of ± 1000 cm-1. It can therefore, be used for the design of new phosphors belonging to this family. In a second part, both models were used to identify the nature of luminescence in Bi3+-doped oxides. For this purpose, a method combining the mentioned models along with the values of the Stokes shift was found reliable. In addition, the method was found useful to explain the change in luminescent properties of YVO4:Bi3+ under high pressure. In the third part, the two models were used to explore the luminescence of Sb3+-doped oxides by analogy with Bi3+. However, the results were not good enough to identify the nature of luminescence in these materials. The reason could be related to the off-centered position of the dopant (Sb3+).

BACKGROUND: Capsule endoscopy (CE) allows for a non-invasive small bowel evaluation for a wide range of gastrointestinal (GI) symptoms and diseases. Capsule technology has been rapidly advancing over recent years, often improving image frequency and quality. The Pillcam SB3 (SB3) capsule is one such technology that offers an adaptive frame rate advantage over the previous versions of the capsule the Pillcam SB2 (SB2). Some have proposed that this improvement in capsule technology may lead to increased diagnostic yields; however, real world clinical data is currently lacking. AIM: To evaluate the clinically relevant findings of SB3 and SB2 capsules in a population of United States veterans. METHODS: A retrospective analysis of 260 consecutive CE studies was performed including 130 SB3 and 130 SB2 capsule studies. Recorded variables included: age, gender, type of capsule, body mass index, exam completion, inpatient status, opioid use, diabetes, quality of preparation, gastric transit time, small bowel transit time, indication, finding, and if the exam resulted in a change in clinical management. The primary outcome measured was the detection of clinically relevant findings between SB3 and SB2 capsules. RESULTS: Mean age of the study population was 67.1 ± 10.4 years and 94.2% of patients were male. Of these 28.1% were on opioid users. The most common indications for capsule procedure were occult GI bleeding (74.6%) and overt GI bleeding (14.6%). Rates of incomplete exam were similar between SB3 and SB2 groups (16.9% 9.2%, = 0.066). The overall rate of clinically relevant finding was 48.9% in our study. No significant difference was observed in SB3 SB2 capsules for clinically relevant findings (46.2% 51.5%, = 0.385) or change in clinical management (40.8% 50.0%, = 0.135). CONCLUSION: Our study found no significant difference in clinically relevant findings between SB3 and SB2 capsules.