18 research outputs found

    Over excitation limiter for synchronous generators with labVIEW

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    18th IEEE International Power Electronics and Motion Control Conference (IEEE PEMC) -- AUG 26-30, 2018 -- World Trade Ctr, Budapest, HUNGARYWOS:000462062900063The excitation control system has two functions, which are also referred to as performance requirements. The first is to provide the DC electric energy to the excitation winding of the synchronous generator and thus to provide the rated voltage value at the generator terminals. The second is to perform the controlling, limiting and protection functions necessary for a successful operation of the power system. Any system depending on special application and excitation includes some or all of these functions. In this study, a novel and functional user interface developed with LabVIEW for over excitation limiter (OEL) have been presented. This interface provides monitoring, recording, range comparing and protection for OEL, frequency and voltage quantities with the enable/disable functions for all actions.IEEE, Budapest Univ Technol & Econ, IEEE Ind Elect Soc, IEEE Ind Applicat So

    Design and loss analysis of LCL filter inductors for two-level and three-level inverters

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    Grid connected inverters with LCL output filters are widely used in exporting energy generated from renewable energy sources. The LCL filter and inductors used in this filter has important effect on inverter performance. Although it is different in high power levels nowadays, powder cores are commonly used in inductor design in low and medium power levels. In this study, inductors for LCL filter of the grid-connected inverter are designed. The co-simulation studies are performed and performance and losses of the designed filter is analyzed for two-level and three-level inverter topologies. It is seen that, total losses of the LCL filter of three-phase three-level inverter is 35.9% lower than two-level inverter

    Physician-reported ECOG-PS versus patient-reported (self) ECOG-PS: Which one is a better predictor of survival in cancer?

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    The aim of this study is to determine the discrepancy and agreement between Eastern Cooperative Oncology Group Performance Status (ECOG-PS) scores evaluated by doctors and patients and examine the factors that influence the performance evaluation of doctors and patients. This study is a prospective and descriptive case-control study. General, demographic, and oncologic data of the patients were collected. e-control study. General, demographic, and oncologic data of the patients were collected. Patient-Reported Outcomes Measurement Information System (PROMIS) anxiety and depression surveys were conducted to determine patients' levels of anxiety and depression, and at the same time, both the doctors and the patients were asked to determine their performance status. As a result, the discrepancy in performance evaluation between the patient and the doctor, the factors affecting this discrepancy, and its effect on progression and survival were examined. 277 patients were included. 146 (52.7%) were male, and 131 (47.3%) were female. The most common cancers were breast cancer (17.7%, n=49) and lung cancer (17.3%, n=48). It was found that the doctors' assessment of patient performance increased the progression risk by 3.1 times (HR: 3.080, 95% CI: 1,671-5,675) in ECOG-PS 2 compared to ECOG-PS 0 and by 5 times (HR: 4.980, 95% CI 1.405-17.646) in ECOG-PS 3 compared to ECOG-PS 0. Our study determined a weak agreement between the doctor and patient in terms of performance assessment. The most significant reason for this discrepancy was found to be due to the levels of depression or anxiety in patients. In conclusion, it was demonstrated that the performance evaluations determined by doctors are more accurate and meaningful in terms of progression and survival results compared to those determined by patients. [Med-Science 2023; 12(3.000): 827-52

    HMG-CoA reductase inhibitor rosuvastatin improves abnormal brain electrical activity via mechanisms involving eNOS

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    WOS: 000346243100032PubMed ID: 25453767Apart from its repressing effect on plasma lipid levels, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors exert neuroprotective functions in animal models of neurodegenerative disorders. In view of these promising observations, we were interested in whether HMG-CoA reductase inhibition would affect epileptiform activity in the brain. To elucidate this issue, atorvastatin, simvastatin and rosuvastatin were administered orally at a dose of 20 mg/kg each for 3 days and their anti-epileptic activities were tested and compared in rats. Epileptiform activity in the brain was induced by an intracortical penicillin G injection. Among HMG-CoA reductase inhibitors, simvastatin-treatment was less effective in terms of spike frequency as compared with atorvastatin- and rosuvastatin-treated animals. Atorvastatin treatment reduced spike frequencies and amplitudes significantly throughout the experiment. However, the most pronounced anti-epileptic effect was observed in rosuvastatin-treated animals, which was associated with improved blood-brain barrier (BBB) integrity, increased expression of endothelial nitric oxide synthase (eNOS) mRNA and decreased expressions of pro-apoptotic p53, Bax and caspase-3 mRNAs. Inhibition of eNOS activity with L-NG-Nitroarginine Methyl Ester (L-NAME) reversed the anti-epileptic effect of rosuvastatin significantly. However, L-NAME did not alter the effect of rosuvastatin on the levels of p53, Bax and caspase-3 mRNA expression. Here, we provide evidence that among HMG-CoA reductase inhibitors, rosuvastatin was the most effective statin on the reduction of epileptiform activity, which was associated with improved BBB permeability, increased expression of eNOS and decreased expressions of pro-apoptotic p53, Bax and caspase-3. Our observation also revealed that the anti-epileptic effect of rosuvastatin was dependent on the increased expression level of eNOS. The robust anti-epileptic effect encourages proof-of-concept studies with rosuvastatin in human epilepsy patients with hypercholesterolemia.European Molecular Biology Organization (EMBO); Turkish Academy of Sciences (TUBA/GEBIP)This work was supported by European Molecular Biology Organization (EMBO) (installation grant) and Turkish Academy of Sciences (TUBA/GEBIP)

    Cisplatin plus paclitaxel and bevacizumab versus carboplatin plus paclitaxel and bevacizumab for the first-line treatment of metastatic or recurrent cervical cancer

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    OBJECTIVE: Cisplatin-paclitaxel and bevacizumab is a frequently used treatment regimen for metastatic or recurrent cervical cancer, and carboplatin-paclitaxel and bevacizumab are also among the recommended regimens. In this study we aimed to evaluate the efficacy of these two regimens for the treatment of metastatic or recurrent cervical cancer. METHODS: Patients with metastatic or recurrent cervical cancer treated with cisplatin-paclitaxel and bevacizumab or carboplatin-paclitaxel and bevacizumab were retrospectively evaluated in this study. The clinical and demographic characteristics of patients in each group were evaluated. Median overall survival, progression-free survival, and response rates between the two groups were compared. RESULTS: A total of 250 patients were included. Overall, the numbers of patients with recurrent disease and metastatic disease were 159 and 91, respectively. The most common histologic subtype was squamous cell carcinoma (83.2%). The median duration of follow-up was 13.6 (range 0.5-86) months. The median progression-free survival was 10.5 (95% CI 9.0 to 11.8) months in the cisplatin-paclitaxel and bevacizumab group (group 1), and 10.8 (95% CI 8.6 to 13.0) months in the carboplatin-paclitaxel and bevacizumab group (group 2) (HR 1.20; 95% CI 0.88 to 1.63; p=0.25). The median overall survival was 19.1 (95% CI 13.0 to 25.1) months in group 1 and 18.3 (95% CI 15.3 to 21.3) months in group 2 (HR 1.28; 95% CI 0.91 to 1.80; p=0.15). CONCLUSIONS: There is no survival difference between cisplatin or carboplatin combined with paclitaxel and bevacizumab in metastatic or recurrent cervical cancer

    Suboptimal use of non-vitamin K antagonist oral anticoagulants: Results from the RAMSES study

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    WOS: 000384041400052PubMed ID: 27583892This study aimed to investigate the potential misuse of novel oral anticoagulants (NOACs) and the physicians' adherence to current European guideline recommendations in real-world using a large dataset from Real-life Multicenter Survey Evaluating Stroke Prevention Strategies in Turkey (RAMSES Study).RAMSES study is a prospective, multicenter, nationwide registry (ClinicalTrials.gov identifier NCT02344901). In this subgroup analysis of RAMSES study, patients who were on NOACs were classified as appropriately treated (AT), undertreated (UT), and overtreated (OT) according to the European Society of Cardiology (ESC) guidelines. The independent predictors of UT and OT were determined by multivariate logistic regression.Of the 2086 eligible patients, 1247 (59.8%) received adequate treatment. However, off-label use was detected in 839 (40.2%) patients; 634 (30.4%) patients received UT and 205 (9.8%) received OT. Independent predictors of UT included >65 years of age, creatinine clearance 50mL/min, urban living, existing dabigatran treatment, and HAS-BLED score of <3, whereas that of OT were creatinine clearance <50mL/min, ongoing rivaroxaban treatment, and HAS-BLED score of 3.The suboptimal use of NOACs is common because of physicians' poor compliance to the guideline recommendations in patients with nonvalvular atrial fibrillation (NVAF). Older patients who were on dabigatran treatment with good renal functions and low risk of bleeding were at risk of UT, whereas patients who were on rivaroxaban treatment with renal impairment and high risk of bleeding were at risk of OT. Therefore, a greater emphasis should be given to prescribe the recommended dose for the specified patients
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