Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

PURPOSE: This study examined the surgical outcomes after pars plana vitrectomy in patients with proliferative diabetic retinopathy at various stages of posterior vitreous detachment. The investigation assessed the changes in visual acuity and the frequency of complications associated with each stage of detachment. METHODS: This retrospective, single-site, single-surgeon study reviewed 328 medical records of patients at Beth Israel Deaconess Medical Center (Boston, MA) requiring pars plana vitrectomy (PPV) for complications of proliferative diabetic retinopathy between 2000 and 2017. The 328 patients were separated into 4 groups based on their vitreous status (Stages 0 and 1, Stage 2, Stage 3, and Stage 4). Preoperative characteristics were collected, including best-corrected visual acuity (BCVA) and diabetes duration. Complications, visual acuity, and reoperation data were collected postoperatively. RESULTS: Sixty-one percent of the patients in the combined group (Stages 0 and 1), 56% in Stage 2, 67% in Stage 3, and 77% in Stage 4 did not require a revision PPV. Thirteen percent of the patients in the combined group, 13% in Stage 2, 5% in Stage 3, and 0% in Stage 4 required a revision PPV for retinal detachment. This represented a statistically significant difference between the groups (p = 0.0254). The combined group had a postoperative change in BCVA of 0.31 compared with 0.29 for Stage 2, 0.67 for Stage 3, and 0.90 for Stage 4. These BCVA changes represented a statistically significant difference (p = 0.0001) between the groups. CONCLUSIONS: This study shows that having a preoperative posterior vitreous detachment leads to improved visual acuity postoperatively and decreased chance of developing a postoperative retinal detachment. The study also indicates that increased vitreoretinal traction results in less change in visual acuity and an increase in complications. Further research is needed to validate these findings.

The first aim of this work is to describe the way in which the term apposition is defined in French and Czech linguistics. The second aim is to examine the use of one type of French apposition in journalistic and legal texts and to find out which equivalents are used in the Czech language for these expressions. The work is divided into theoretical and practical part. The theoretical part includes a description of different approaches of apposition in the French and Czech language. The practical part begins with a choice of one definition of apposition which will be further used in the corpus analysis. The corpus analysis is conducted by using the corpus InterCorp and its subject is to examine the function and frequency of French apposition in journalistic and legal texts and furthermore to analyse its Czech equivalents.

Low-energy resonant processes in collisions of electrons, atoms, ions and molecules significantly contributed to the evolution of the early Universe. Much attention has not yet been paid to processes involving lithium atoms and ions. In this thesis, we present the theoretical description of two associa- tive detachment processes of Li with H− and H with Li− within the nonlocal resonant theory. The nonlocal resonant models were constructed from poten- tial energy curves computed by the MOLPRO package of ab initio programs and from electron-molecule scattering data obtained from R-matrix calcula- tions by the UK molecular R-matrix suite of codes. The Lippman-Schwinger equation describing the nuclear motion was solved by the Schwinger-Lanczos algorithm. We developed a new method, which is based on the singular value decomposition method and separates the coupling potential. We predict sev- eral orders of magnitude difference between the temperature-dependent rate constants of the studied collisions at temperatures below 1000 K.

Magister Curationis - MCur / Literature shows that cataracts are the leading cause of blindness globally and nationally. Retinal detachment has also been a substantial problem both globally and nationally. Both of these conditions are prevalent in patients of 50 years and older. The treatment for both conditions is for surgery to be performed. In the Western Cape the three leading hospitals do not have ophthalmic pre-operative and post-operative protocols.Review question:What are the best practices to manage pre-operative and post-operative nursing care in patients waiting for cataract and retinal detachment surgery? bjectives:1. To determine the best practice in pre-operative and post-operative care in patients who have undergone cataract and/or retinal detachment surgery regarding: health education offered by nurses, counselling to prevent psychological effects, and positioning to prevent physical complications. 2. To develop a framework based on systematic reviews for pre-operative and post-operative ophthalmic nursing care in South Africa. Methodology: A systematic review using the guide by the Centre for Reviews and Dissemination was done, and studies were identified by searching various electronic databases and visually scanning reference lists from the relevant studies. Studies that were included were evidence-based. All study types were considered and the studies were selected based on the title and, where available, the abstract. These were then assessed against the inclusion criteria. A narrative synthesis was used. Finally the evidence was summarised and a framework was drawn up, focusing on pre-operative and post-operative nursing care for cataract and retinal detachment surgery

L’invasion de la matrice extracellulaire est le premier obstacle que les tumeurs solides rencontrent lors de leur dissémination métastatique. Il existe deux mécanismes principaux: 1) la transition épithélio-mésenchymateuse au cours de laquelle les cellules épithéliales, à l’échelle individuelle, perdent leur cohésion intercellulaire et acquièrent des capacités de motilité pour quitter leur site d’origine ; 2) l’invasion collective dans laquelle des cellules en groupe coopèrent pour migrer collectivement en se frayant un passage à travers le microenvironnement. Dans les modèles murins, on sait maintenant que des groupes ou agrégats de cellules tumorales circulantes issus du détachement de tumeurs primaires présentent une capacité accrue à coloniser des organes à distance. Cependant, les facteurs et mécanismes sous-jacents conduisant au détachement des cellules tumorales en groupe sont peu connus. Pour étudier ces mécanismes, nous avons utilisé des sphéroïdes tumoraux, modèle expérimental tri-dimensionnel (3D), qui mime le microenvironnement ainsi que les caractéristiques morphologiques et fonctionnelles de la tumeur primaire. Nos résultats indiquent que l'inhibiteur de l’activateur du plasminogène (PAI-1), une protéine matricellulaire trouvée en forte concentration dans les cancers invasifs, favorise le détachement en groupe et l’invasion collective de cellules du cancer du sein (lignée cellulaire MCF7) et du colon (lignée cellulaire HCT116) organisées en sphéroïdes tumoraux. PAI-1 a des propriétés dé-adhésives sur des cellules étalées en monocouche sur des matrices pro-adhésives et génère l’agrégation des cellules entre-elles. Ces cellules conservent leurs caractéristiques épithéliales malgré une modification importante de la dynamique du réseau d'actine.Nos résultats suggèrent que les récepteurs cellulaires de la famille des lipoprotéines de basse densité (LDL-R) sont impliqués dans les propriétés dé-adhésives de PAI-1. Dans la cellule, la transduction du signal passe par les kinases ROCK (kinase associée à la GTPase RhoA) et Janus (JAK), ce qui conduit à une phosphorylation de la chaîne légère de la myosine II (MLC2), nécessaire pour l’activité contractile de la myosine et des facteurs de transcription STAT3. En outre, ROCK, un régulateur connu de la contraction du cytoskelette d’actomyosine, est également impliqué dans l'activation de STAT3. L'inhibition de ROCK ou JAK rétablit l’adhésivité des cellules en 2D et réduit leur migration en 3D. Nos données suggèrent que PAI-1 génère des zones de forte activité contractile membranaire dans les cellules en périphérie de la tumeur via ROCK-MLC2 et JAK-STAT, ce qui promeut le détachement de groupe de cellules hautement invasives. Ce nouvel axe de signalisation fonctionnelle de PAI-1 représente une cible anti-métastatique potentielle. / Invasion of the extracellular matrix is the first obstacle that solid tumours encounter during their metastatic dissemination. There are two main mechanisms: 1) epithelial to mesenchymal transition wherein epithelial cells lose their intercellular cohesion and convert to individual migratory behaviours to escape their point of origin; 2) invasion in a collective manner, in which a group or cluster of cohesive cancer cells detaches from the tumour mass and progressively, pushes its way through the microenvironment. It is now known that circulating tumour cell clusters may result from the evasion of cohesive small groups of cells from tumours and such tumour cell clusters display an increased propensity to colonize distant organs in mouse models. However, the extracellular factor/s and the underlying mechanism that enable cell detachment, as clusters are largely unknown. To study the process of tumour cell detachment and invasion, we used a three-dimensional (3D) multicellular tumour spheroid (MCTS) model, which mimics the microenvironment as well as morphological, functional and symmetric geometry features of the primary tumour. Our results strongly indicate that the plasminogen activator inhibitor-1 (PAI-1), a matricellular protein found in high concentration at the invasive front of most cancers, promotes cancer cell cluster detachment and a collective invasion phenotype within MCTS of breast cancer MCF7 and colon cancer HCT116 cell lines. We found that PAI-1 has a de-adhesive effect which induced a multilayered cell clustering of cells spread out on a pro-adhesive matrices in 2D monolayer cultures. Cells retained their epithelial characteristics and membrane-localized E-cadherin despite significant modification of actin dynamics. PAI-1 functions as a de-adhesive molecule most likely involved low-density lipoprotein receptors at the cell surface. We report that the downstream intracellular events may be mediated through the Rho-associated kinase (ROCK) and Janus kinases (JAK) signalling pathway, resulting in phosphorylation of either myosin light chain 2 (MLC2), which is required for myosin II-mediated contractility or STAT3 transcription factors. In addition, ROCK, a known contributor to actomyosin contractility is involved in STAT3 phosphorylation and activation. Inhibition of ROCK and JAK restored adhesion of cells on 2D substratum and reduced their migration/invasion within 3D MCTS model. Our data support a model in which PAI-1 generates actomyosin contractility and high membrane activity at the tumour periphery in a JAK-STAT/ROCK-MLC2 dependent manner promoting the detachment of highly invasive cell clusters. This novel axis of functional signalling of PAI-1 is a potential anti-metastasis target.

No description available.

The role of cross field transport and volume recombination are of vital importance for a satisfactory understanding of the plasma edge in magnetically confined devices such as a Tokamak. Plasma fluctuations may travel cross field with significant velocities and play a central role in plasma transport. Cross field transport has been seen to be anomalous in most devices under a very broad range of experimental conditions. In recent years a clear indication of the relation between fluctuation, cross field particle transport and recombination has been reported.The University of Manchester Linear System (the ULS) has been used to observe the Balmer emission of the recombining plasma interacting with a dense neutral Hydrogen gas. The ULS is a device made of a cylindrical vacuum vessel 1.5 m long and 15 cm in radius. The plasma is formed in a separate chamber by a duoplasmatron source in the Demirkhanov configuration; the arc current was limited to 15 A and the potential drop was 100 V. The device is surrounded by a linear solenoid which was used to magnetize the plasma. The highest magnetic field was .1 T. Typical electron temperature in the device spans .1 to 10 eV, and the density 1. E+16 to 5. E+19.Diagnostic includes Langmuir probe and visible spectrometers. In addition, the DivCam imaging system originally designed and built to obtain 2D images of the MAST spherical Tokamak Scrape Off Layer, was used. The DivCam imaging system has enabled to obtain high resolution images of the plasma emission when interacting with the neutral gas. It appears evident that the Electron-Ion Recombination is strongly dependent upon radial transport of plasma particles: light emission attributed to EIR is only observed at a large cross field distance from the plasma source. Moreover, fast imaging of the plasma has also shown the presence of a plasma filament forming and propagating crossfield at the same region of the plasma where the EIR light is observed.To interpret the experimental observations obtained with DivCam, the OSM 1D fluid plasma solver and the EIRENE neutral Monte Carlo solver have been implemented in the linear geometry of the ULS linear system. Both the OSM and the EIRENE solvers were originally intended for tokamak and large magnetic confinement devices. Modelling of the EIR emissivity in the ULS device has demonstrated the importance of the inclusion of turbulent and blob transport in the model to obtain reasonable agreement between the observations and the theoretical predictions. The central density of the plasma filament has been estimated to be approximately .7 E+19 m-3 using EIRENE results.The emission attributed to hydrogenic ions (negative atomic H- and positive molecular ions H2+) and related to Molecular Assisted Recombinations can be estimated within EIRENE using the AMJUEL database. The database provides ion population estimations for three different collisional regimes: in the first regime a large population of vibrational excited hydrogen molecules are assumed to exist within the plasma volume; the second assumes strong Charge Exchange reactions and not vibrational excited molecule; the third assumes electron impact collisions with ground states molecule to be the only ion source. A reasonable agreement between the observations and the EIRENE prediction is only found when using the third estimation suggesting that molecular excitation and charge exchange processes are relatively unimportant under the experimental conditions considered.

Chaque sujet doit composer avec le manque en tant que "parlêtre" et "sujet du désir". Le symptôme qui révèle le manque a son lot de souffrances. Celles-ci submergent parfois le sujet dans le trou du réel en le déstabilisant. Comment aider à donner du sens au manque dévoilé par la souffrance dans le symptôme ? Existe-t-il une façon optimale de se positionner face au manque ? Que faire avec le réel ? Le modèle psychanalytique, avec l'expérience du transfert/contre-transfert, donne une réponse et une possibilité de sortie. Dans cette thèse nous soumettrons des pistes pour faire face au manque et au réel inhérent. Lacan nous dit qu'à la fin de l'analyse il peut y avoir un lien inédit avec le symptôme, lien qui consiste à admette le "jouis" qui fonde le "suis", c’est-à-dire à assumer le fait d'avoir un manque qui rendra le sinthome pur. Le sujet se positionnera autrement. Il continuera à aller de l'avant, singulièrement inséré dans son environnement avec une nouvelle conscience, en établissant un maximum de liens optimaux avec les autres et son milieu. Un certain nombre d'études concluent que l'homme n'a pas de but extérieur à lui-même : il serait son propre but. Or le positionnement féminin propose une autre sortie qui ouvre le sujet à l'infini impossible à saisir mais toujours possible à entrevoir. Maître Eckhart l'a illustré en voyant le manque comme une voie de liberté et de réalisation dans cet impossible. Le sujet, libre de sa castration tentera de cerner un bout du réel, encore et encore, mais sans jamais s'en débarrasser. / Each individual has to face its dependence towards the "parlêtre" and the "subject of desire". The symptom that reveals its dependence is painful, and can sometimes overwhelms the subject by projecting him in an abysm of destabilizing reality. How can we help people finding meaning to this dependence now revealed and its painful symptom? Is there an ideal way to take action towards this dependence? What can be done with this reality? The psychoanalytic model, with the transfer/against transfer experience, gives an answer and a possible way to overcome the issue. In this thesis, clues will be given so that one can overcome the dependence and its inherent reality. Lacan tells us that at the end of the analyses, it can be a new link with the symptom, link which consists of admitting the "enjoy" which found the "be", that is to say to assume the fact that the dependence exists which makes the symptom pure. The individual will have a different opinion. He will continue on going forward, well established in his environment with a new consciousness. Some studies suggest that human being has not external goal in relation to himself: he would be his own goal. However the female positioning may open a new way offering the subject to the elusive infinity that we are always able to glimpse but not to grasp. Maître Eckhart illustrates it, showing the lack as a way of freedom and achievement in the suffering situation. The subject, free from his own castration will try again and again to catch a piece of real without ever getting rid of it.

<div> <div> <div> <div> <div> <p>This study follows a resource-recovery-adaptation approach, where nurses’ personal and external resources, a potential recovery mechanism, and a positive outcome are operationalized from an existing dataset obtained from a multi-state sample of registered nurses in the United States. Data was collected in two Press Ganey surveys, the Employee Survey and the Resilience Survey, in 2018. The surveys were administered in over one thousand healthcare organizations, including acute care hospitals, medical practice groups, outpatient surgery centers, children's hospitals, home health organizations as well as other ancillary services (Press Ganey Associates, 2018). The surveys contained items measuring nurses’ perceptions of their organizations (i.e., community commitment, diversity and inclusion, employee care, compensation, and service and quality), their direct work environments (i.e., leadership, teamwork, staffing level, and job resources), and their work (i.e., job stress, job satisfaction, commitment to the nursing profession, and work-life balance), as well as nurses’ demographic characteristics (i.e., age, sex, race, tenure, shift, and full-time/part-time status).</p></div></div></div> </div> </div>