Επεξεργασία δορυφορικών παρατηρήσεων στη Νήσο Μεγίστη με το λογισμικό GAMIT/GLOBK

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

Autologous repair of an internal carotid artery aneurysm by resection, caliber reduction, and external mesh tube reinforcement in a 9-year-old boy

Extracranial internal carotid artery aneurysms in children are rare, with a reported incidence of 0.5% to 1.9% in internal carotid artery aneurysm operations compared with all carotid operations in adult patients. We report a case of surgical reconstruction of an extracranial internal carotid artery aneurysm in a 9-year-old boy. Our patient complained of episodic neck pain on the left site under the mastoid process for the last year. The child was otherwise healthy. Autologous reconstruction without graft interposition was planned. Surgical repair was performed by resection of the main body of the aneurysm and restoration of the arterial continuity with end-to-end anastomosis. Because nondilated proximal and distal vessels could not be approximated, the most distal end of the aneurysm was tapered over a mandril. To prevent redilation, a tubular polyester external stent was fitted around the diseased segment

An unusual presentation of a sarcoidosis that mimicked lymphatic metastatize non small cell lung carcinoma in positron emission tomography: a case report

In the last decade, several sophisticated and accurate imaging methods such as positron emission tomography have been developed in order to evaluate malignant potential in enlarged mediastinal lymph nodes. This case illustrates an unusual presentation of sarcoidosis that mimicked lymphatic metastases of non small cell lung carcinoma. The reported high specificity and sensitivity of positron emission tomography-Computer Tomography regarding mediastinal staging could lead in same cases of false positives to a delaying of stage adapted therapy of non small cell lung carcinoma, showing that despite the recent advances of imaging techniques, such as positron emission tomography-computer tomography, several limitations of this imaging technique are still existing

Nutritional risk index is a better predictor of early mortality than conventional nutritional markers after transcatheter aortic valve replacement: A prospective cohort study

Background: Nutritional risk index (NRI) has been shown to better predict survival than body mass index (BMI) or albumin after several cardiovascular interventions. Under assessment herein is whether NRI can have higher predictive value than conventional parameters for short-term survival after transcatheter aortic valve replacement (TAVR).Methods: A prospective cohort study was performed. In-hospital, 1-month and 3-month survival was evaluated. Since most patients undergoing TAVR are over 65, the NRI definition for a geriatric population (GNRI) was used. The impact of baseline BMI, albumin levels, and GNRI on in-hospital and short-term survival was assessed.Results: One hundred fifty two patients aged 82 ± 5.4 were included. In-hospital, 1-month, and 3-month mortality was 5.3%, 5.9%, and 9.2%, respectively. Mean GNRI was 112.7 ± 11.9, and was significantly lower in patients who died in-hospital (101.0 ± 8.8 vs. 113.3 ± 11.7), at 30 days (103.4 ± 10.9 vs. 113.3 ± 11.7), and at 90 days (104.0 ± 9.6 vs. 113.6 ± 11.8) than in survivors (all, p < 0.05). Three-month mortality in patients with no nutritional risk was 6.8% (9/132) vs. 25% (5/20) in patients with malnutrition (p = 0.022). In univariate analysis, GNRI predicted in-hospital, 30-day, and 90-day mortality (all, p < 0.05). Predictive value remained significant after adjusting for age, EuroSCORE II, and STS-Score (p < 0.05). Based on receiver operating curves, GNRI (AUC: 0.73) showed a betterdiscrimination for 3-month mortality than albumin (0.69), weight (0.67) or BMI (0.62). The optimal cut-off value was 109.8.Conclusions: The geriatric nutritional risk index predicts short-term mortality after TAVR and has a higher discriminating ability than other commonly used nutritional variables. It is a simple parameter that identifies those patients who could benefit from pre-procedural nutritional therapy

Conversion from off-pump to on-pump coronary artery bypass grafting: impact of surgeon and anaesthetist experience

OBJECTIVES Intraoperative conversion from off-pump to on-pump coronary artery bypass grafting (CABG) is associated with increased postoperative morbidity and mortality. The aim of this study is to assess the impact of surgeon and anaesthetist experience on the conversion rate. METHODS We performed a retrospective analysis of the data of all patients who underwent planned off-pump CABG in a single centre in 2007-2021, some of whom were non-electively converted to on-pump. Surgeon and anaesthetist experience were assessed by the number of off-pump bypass procedures per year. Multivariable logistic regression analysis was used to assess the impact of surgeon and anaesthetist experience on conversion rate. RESULTS A total of 2742 patients met the inclusion criteria. Ninety-four (3.4%) patients underwent non-elective conversion to on-pump surgery. Converted patients had significantly higher mortality [11 (11.7%) vs 35 (1.3%), P < 0.0001] in comparison to non-converted patients. Anaesthetist experience was found to be a risk factor for conversion (P = 0.011). Surgeon experience did not significantly affect conversion rate (P = 0.51). Other risk factors for conversion were female gender [odds ratio 2.65 (95% confidence interval 1.65-4.26), P = 0.0001] and left ventricular ejection fraction ≤35% [odds ratio 1.91 (95% confidence interval 1.05-3.49), P = 0.040]. CONCLUSIONS Conversion from off-pump to on-pump CABG is associated with worse postoperative outcomes. Limited experience of anaesthetists in off-pump bypass surgery is associated with a higher conversion rate

The role of ETG modes in JET-ILW pedestals with varying levels of power and fuelling

We present the results of GENE gyrokinetic calculations based on a series of JET-ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels of power and gas fuelling. We show that turbulence due to electron-temperature-gradient (ETGs) modes produces a significant amount of heat flux in four JET-ILW discharges, and, when combined with neoclassical simulations, is able to reproduce the experimental heat flux for the two low gas pulses. The simulations plausibly reproduce the high-gas heat fluxes as well, although power balance analysis is complicated by short ELM cycles. By independently varying the normalised temperature gradients (omega(T)(e)) and normalised density gradients (omega(ne )) around their experimental values, we demonstrate that it is the ratio of these two quantities eta(e) = omega(Te)/omega(ne) that determines the location of the peak in the ETG growth rate and heat flux spectra. The heat flux increases rapidly as eta(e) increases above the experimental point, suggesting that ETGs limit the temperature gradient in these pulses. When quantities are normalised using the minor radius, only increases in omega(Te) produce appreciable increases in the ETG growth rates, as well as the largest increases in turbulent heat flux which follow scalings similar to that of critical balance theory. However, when the heat flux is normalised to the electron gyro-Bohm heat flux using the temperature gradient scale length L-Te, it follows a linear trend in correspondence with previous work by different authors

Spectroscopic camera analysis of the roles of molecularly assisted reaction chains during detachment in JET L-mode plasmas

The roles of the molecularly assisted ionization (MAI), recombination (MAR) and dissociation (MAD) reaction chains with respect to the purely atomic ionization and recombination processes were studied experimentally during detachment in low-confinement mode (L-mode) plasmas in JET with the help of experimentally inferred divertor plasma and neutral conditions, extracted previously from filtered camera observations of deuterium Balmer emission, and the reaction coefficients provided by the ADAS, AMJUEL and H2VIBR atomic and molecular databases. The direct contribution of MAI and MAR in the outer divertor particle balance was found to be inferior to the electron-atom ionization (EAI) and electron-ion recombination (EIR). Near the outer strike point, a strong atom source due to the D+2-driven MAD was, however, observed to correlate with the onset of detachment at outer strike point temperatures of Te,osp = 0.9-2.0 eV via increased plasma-neutral interactions before the increasing dominance of EIR at Te,osp &lt; 0.9 eV, followed by increasing degree of detachment. The analysis was supported by predictions from EDGE2D-EIRENE simulations which were in qualitative agreement with the experimental observations

Shattered pellet injection experiments at JET in support of the ITER disruption mitigation system design

A series of experiments have been executed at JET to assess the efficacy of the newly installed shattered pellet injection (SPI) system in mitigating the effects of disruptions. Issues, important for the ITER disruption mitigation system, such as thermal load mitigation, avoidance of runaway electron (RE) formation, radiation asymmetries during thermal quench mitigation, electromagnetic load control and RE energy dissipation have been addressed over a large parameter range. The efficiency of the mitigation has been examined for the various SPI injection strategies. The paper summarises the results from these JET SPI experiments and discusses their implications for the ITER disruption mitigation scheme