49 research outputs found
Konstantin Nikolakopoulos, Athanasios Vletsis, Vladimir Ivanov, Orthodoxe Theologie zwischen Ost und West.
No full textKonstantin Nikolakopoulos, Athanasios Vletsis, Vladimir Ivanov, Orthodoxe Theologie zwischen Ost und West.. In: Revue des études byzantines, tome 62, 2004. pp. 318-320
Six months follow up of a single intravitreal injection of ocriplasmin for symptomatic vitreomacular adhesion
No full textPurpose: To evaluate the efficacy and the safety of the enzymatic vitreolysis with a single intravitreal injection of ocriplasmin 125 μg across a group of patients with symptomatic vitreomacular adhesion (sVMA) during 6 months follow up.
Design: A randomized, placebo-controlled, double-masked, 6-month follow up study.
Participants: A total of 28 patients (12 M / 16F) (19 receiving ocriplasmin; 9 receiving placebo), mean aged 71 years old, diagnosed with sVMA, VMT, FTMH e ERM by optical coherence tomography.
Methods: A single intravitreal injection of ocriplasmin 125 μg or placebo. Primary endpoint was sVMA resolution or FTMH closure. Secondary endpoint included the integrity of the external membrane and the inner and outer segments of the photoreceptor interface using OCT. The evaluation was carried out at baseline and during 6 months after intravitreal injection of ocriplasmin or placebo.
Results: After a 6 months follow-up period, the rate of VMA resolution was 42.1% in the Ocriplasmin group vs the 22% in the placebo group. FTMH closure rate was 50% in the Ocriplasmin group vs 0% in the placebo group. The best results were optained within 28 days from the treatment. No case of uveitis, endophthalmitis, retinal tears, retinal detachment or bleeding during follow-up were reported. One patient reported floaters and transitional photopsias.
Conclusions: The study confirmed the efficacy and safety of Ocriplasmin injection for patients with VMT, including when associated with full-thickness macular holes during six months follow up. Long term studies are certainly needed to confirm these results
Elements and evolutionary determinants of genomic divergence between paired primary and metastatic tumors.
No full textCan metastatic-primary (M-P) genomic divergence measured from next generation sequencing reveal the natural history of metastatic dissemination? This remains an open question of utmost importance in facilitating a deeper understanding of metastatic progression, and thereby, improving its prevention. Here, we utilize mathematical and computational modeling to tackle this question as well as to provide a framework that illuminates the fundamental elements and evolutionary determinants of M-P divergence. Our framework facilitates the integration of sequencing detectability of somatic variants, and hence, paves the way towards bridging the measurable between-tumor heterogeneity with analytical modeling and interpretability. We show that the number of somatic variants of the metastatic seeding cell that are experimentally undetectable in the primary tumor, can be characterized as the path of the phylogenetic tree from the last appearing variant of the seeding cell back to the most recent detectable variant. We find that the expected length of this path is principally determined by the decay in detectability of the variants along the seeding cell's lineage; and thus, exhibits a significant dependence on the underlying tumor growth dynamics. A striking implication of this fact, is that dissemination from an advanced detectable subclone of the primary tumor can lead to an abrupt drop in the expected measurable M-P divergence, thereby breaking the previously assumed monotonic relation between seeding time and M-P divergence. This is emphatically verified by our single cell-based spatial tumor growth simulation, where we find that M-P divergence exhibits a non-monotonic relationship with seeding time when the primary tumor grows under branched and linear evolution. On the other hand, a monotonic relationship holds when we condition on the dynamics of progressive diversification, or by restricting the seeding cells to always originate from undetectable subclones. Our results highlight the fact that a precise understanding of tumor growth dynamics is the sine qua non for exploiting M-P divergence to reconstruct the chronology of metastatic dissemination. The quantitative models presented here enable further careful evaluation of M-P divergence in association with crucial evolutionary and sequencing parameters
Dynamic request assignment in aerial ride sharing operations
No full textThe concept of Urban Air Mobility (UAM) services was created mainly in response to traffic congestions. In this research we focus on UAM services such as those provided by Uber Elevate. We therefore present a framework to solve the Urban Air Mobility Problem with Time Windows (UAMP-TW) under dynamic demand, using an Adaptive Large Neighborhood Search (ALNS) algorithm. The objective of this study is to maximize the operational profit and consider customer satisfaction. Satisfaction is measured by two factors: (1) deviation from desired departure time to actual departure time and (2) deviation from nominal trip duration to actual trip duration. In our analysis we aim to determine a relationship between customers and their contribution towards profit. We address this by running simulation instances that cover three operational scenarios: a morning and evening commuter transportation case (scenarios 1 and 2) and the an occurrence of an event at a specific location (scenario 3). Multiple simulation runs indicated stability, for all three instances, due to low variation of the profit from the mean. A sensitivity analysis on the customers' time-window lengths, satisfaction factors and types concluded that customers with higher time-window lengths are more profitable since it is easier to share-rides with other users. The analysis also showed that when the satisfaction factors have a higher weight in the deviation from the departure time than the trip duration, the overall customer satisfaction is increased together with the profit and the percentage of customers who share rides. Scenario 1 has a higher rate of rebalancing empty vehicles because most requests are generated in the suburbs while the depot is located downtown. This leads to a lower vehicle deployment. In scenarios 2 and 3, most requests are generated downtown and thus more vehicles are deployed. Under dynamic demand, the algorithm has an acceptance rate of new requests of about 90% while a penalty is given to customers who cancel a ride. Analysis showed that customers are rejected if an empty vehicle has to rebalance to their location unless they are premium. In terms of the computational efficiency the algorithm is able to handle between 40-50 requests simultaneously.Aerospace Engineering | Air Transport and Operation
Prediction of crack depth and position in vibrating beams using artificial neural networks
No full textThe aim of this paper is to develop a finite element procedure for crack prediction in vibrating beams. Based on this procedure, full frictional contact conditions are introduced between the crack surfaces in order to consider the breathing of crack. The region surrounding the crack is simulated by two-dimensional finite elements. An incremental-iterative procedure is employed to solve the nonlinear dynamic equations governing this problem. The obtained time response is processed with Fast Fourier Transform to extract its frequency components. The first three natural frequencies are input to a trained Artificial Neural Network for depth and position prediction of the crack. This study is validated for a dynamic loading cantilever beam. It is found that the proposed procedure is capable of predicting the crack depth and position with high accuracy
Aligned and Misaligned Wear Pattern in Fluid Film Bearings and Influence on the Rotor Response
No full textJournal bearings are subjected to wear when rub effect happens during the start up or the operation of the rotating system. The wear pattern in many cases is uniformly extended along the width of the bearing. In some other cases the wear pattern is non-uniformly distributed but misaligned along the width, because the rotating shaft inside the bearing operates in misaligned conditions. In this work a rotor bearing system composed of a multi-step rotor and worn fluid film bearings is simulated, in order to notify the effect of the wear on the dynamic characteristics of the system. The bearing wear pattern is considered as aligned, following the Dufrane’s model, or misaligned, when the rotor is whirling misaligned. In the first part of this investigation, the finite element method (FEM) is used in order to solve the Reynolds equation and then to calculate the bearing dynamic characteristics, as functions of Sommerfeld number, L/D ratio and several combinations of journal and wear pattern misalignment angles. The bearing’s stiffness and damping have been adopted in system’s properties during operation. In the second part, the physical system is simulated by considering continuous shaft theory, including hysteretic damping and using the nonlinear bearing stiffness and damping coefficients calculated in the first part. Thus the dynamic response can be calculated. Comparison of the response for aligned and misaligned wear pattern is also included. Notifications for critical speed shift, system anisotropy and additional harmonics in the response spectra are made during system’s virtual start up
