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George J. Papaioannou

Bio: George J. Papaioannou is an academic researcher from National and Kapodistrian University of Athens. The author has contributed to research in topics: Capacitive sensing & Dielectric. The author has an hindex of 27, co-authored 232 publications receiving 2599 citations. Previous affiliations of George J. Papaioannou include Hofstra University & Hoffmann-La Roche.


Papers
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Journal ArticleDOI
TL;DR: To compare the performance of screening for pre‐eclampsia based on risk factors from medical history with the method proposed by The Fetal Medicine Foundation, which uses Bayes' theorem to combine the a‐priori risk from maternal factors, derived by a multivariable logistic model, with the results of various combinations of biophysical and biochemical measurements.
Abstract: Objective To compare the performance of screening for pre-eclampsia (PE) based on risk factors from medical history, as recommended by NICE and ACOG, with the method proposed by The Fetal Medicine Foundation (FMF), which uses Bayes' theorem to combine the a-priori risk from maternal factors, derived by a multivariable logistic model, with the results of various combinations of biophysical and biochemical measurements. Methods This was a prospective multicenter study of screening for PE in 8775 singleton pregnancies at 11–13 weeks' gestation. A previously published FMF algorithm was used for the calculation of patient-specific risk of PE in each individual. The detection rates (DRs) and false-positive rates (FPRs) for delivery with PE < 32, < 37 and ≥ 37 weeks were estimated and compared with those derived from application of NICE guidelines and ACOG recommendations. According to NICE, all high-risk pregnancies should be offered low-dose aspirin. According to ACOG, use of aspirin should be reserved for women with a history of PE in at least two previous pregnancies or PE requiring delivery < 34 weeks' gestation. Results In the study population, 239 (2.7%) cases developed PE, of which 17 (0.2%), 59 (0.7%) and 180 (2.1%) developed PE < 32, < 37 and ≥ 37 weeks, respectively. Screening with use of the FMF algorithm based on a combination of maternal factors, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF) detected 100% (95% CI, 80–100%) of PE < 32 weeks, 75% (95% CI, 62–85%) of PE < 37 weeks and 43% (95% CI, 35–50%) of PE ≥ 37 weeks, at a 10.0% FPR. Screening with use of NICE guidelines detected 41% (95% CI, 18–67%) of PE < 32 weeks, 39% (95% CI, 27–53%) of PE < 37 weeks and 34% (95% CI, 27–41%) of PE ≥ 37 weeks, at 10.2% FPR. Screening with use of ACOG recommendations detected 94% (95% CI, 71–100%) of PE < 32 weeks, 90% (95% CI, 79–96%) of PE < 37 weeks and 89% (95% CI, 84–94%) of PE ≥ 37 weeks, at 64.2% FPR. Screening based on the ACOG recommendations for use of aspirin detected 6% (95% CI, 1–27%) of PE < 32 weeks, 5% (95% CI, 2–14%) of PE < 37 weeks and 2% (95% CI, 0.3–5%) of PE ≥ 37 weeks, at 0.2% FPR. Conclusion Performance of screening for PE at 11–13 weeks' gestation by the FMF algorithm using a combination of maternal factors, MAP, UtA-PI and PlGF, is by far superior to the methods recommended by NICE and ACOG. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

242 citations

Journal ArticleDOI
07 Nov 2005
TL;DR: In this article, the authors investigated both theoretically and experimentally the dielectric charging effects of capacitive RF microelectromechanical system switches with silicon nitride as dielectrics layer, and the amphoteric nature of traps and its effect on the switch operation were confirmed under both positive and negative control voltages.
Abstract: This paper investigates both theoretically and experimentally the dielectric charging effects of capacitive RF microelectromechanical system switches with silicon nitride as dielectric layer. Dielectric charging caused by charge injection under voltage stress was observed. The amphoteric nature of traps and its effect on the switch operation were confirmed under both positive and negative control voltages. It has been confirmed that charging is a complicated process, which can be better described through the stretched exponential relaxation. This mechanism is thermally activated with an activation energy being calculated from the temperature dependence of the capacitance transient response. The charging mechanism, which is responsible for the pull-out voltage and the device failure, is also responsible for the temperature-induced shift of the capacitance minimum bias.

114 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined the wealth effects to U.S. target firms observed at the announcement of acquisition bids made by foreign bidders and found evidence supporting theories that attribute asset value enhancement to corporate multinationality and increased target benefits from competition.
Abstract: This study examines the wealth effects to U.S. target firms observed at the announcement of acquisition bids made by foreign and U.S. bidders. We hypothesize that if the market expects foreign bidders to produce superior takeover gains, the announcement-related excess returns of the targets will reflect these gains when competition forces the foreign bidder to share them with the target. We proxy foreign competition by the relative volume of foreign takeovers in the industry of each target, and find evidence in support of this hypothesis. The evidence supports theories that attribute asset value enhancement to corporate multinationality and increased target benefits from competition in the corporate acquisitions market.

89 citations

Journal ArticleDOI
TL;DR: In this paper, the authors examined the market reaction to listing on the New York Stock Exchange (NYSE) and found that stocks with low liquidity on the OTC exhibit a positive reaction, whereas stocks with high liquidity show a non-positive market reaction around the announcement of the listing application.
Abstract: This study examines the market reaction to listing on the New York Stock Exchange (NYSE). The marketability gains hypothesis states that investors expect liquidity gains for the less liquid over-the-counter (OTC) stocks but not for their liquid counterparts after their listing on the NYSE. The hypothesis is supported even after accounting for other firm-specific news releases. Stocks with low liquidity on the OTC exhibit a positive reaction, whereas stocks with high liquidity show a non-positive market reaction around the announcement of the listing application. The findings imply that the two different marketplaces, NYSE and OTC, are suitable for stocks with different liquidity characteristics.

79 citations

Journal ArticleDOI
TL;DR: The investigation has been performed on PECVD-SiNx dielectric materials deposited under different deposition conditions and the leakage current was found to obey the Poole–Frenkel law.

71 citations


Cited by
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Journal ArticleDOI
TL;DR: This review is intended to give a general background to the use of cyclodextrin as solubilizers as well as highlight kinetic and thermodynamic tools and parameters useful in the study of drug Solubilization bycyclodextrins.

1,674 citations

Journal ArticleDOI
TL;DR: Treatment with low‐dose aspirin in women at high risk for preterm preeclampsia resulted in a lower incidence of this diagnosis than placebo, and there were no significant between‐group differences in the incidence of neonatal adverse outcomes or other adverse events.
Abstract: BackgroundPreterm preeclampsia is an important cause of maternal and perinatal death and complications. It is uncertain whether the intake of low-dose aspirin during pregnancy reduces the risk of preterm preeclampsia. MethodsIn this multicenter, double-blind, placebo-controlled trial, we randomly assigned 1776 women with singleton pregnancies who were at high risk for preterm preeclampsia to receive aspirin, at a dose of 150 mg per day, or placebo from 11 to 14 weeks of gestation until 36 weeks of gestation. The primary outcome was delivery with preeclampsia before 37 weeks of gestation. The analysis was performed according to the intention-to-treat principle. ResultsA total of 152 women withdrew consent during the trial, and 4 were lost to follow up, which left 798 participants in the aspirin group and 822 in the placebo group. Preterm preeclampsia occurred in 13 participants (1.6%) in the aspirin group, as compared with 35 (4.3%) in the placebo group (odds ratio in the aspirin group, 0.38; 95% confidenc...

1,299 citations

Journal ArticleDOI
TL;DR: The cause(s) of preeclampsia and the optimal clinical management of the hypertensive disorders of pregnancy remain uncertain; therefore, it is recommended that every hypertensive pregnant woman be offered an opportunity to participate in research, clinical trials, and follow-up studies.
Abstract: These recommendations from the International Society for the Study of Hypertension in Pregnancy (ISSHP) are based on available literature and expert opinion. It is intended that this be a living document, to be updated when needed as more research becomes available to influence good clinical practice. Unfortunately, there is a relative lack of high-quality randomized trials in the field of hypertension in pregnancy compared with studies in essential hypertension outside of pregnancy, and ISSHP encourages greater funding and uptake of collaborative research in this field. Accordingly, the quality of evidence for the recommendations in this document has not been graded although relevant references and explanations are provided for each recommendation. The document will be a living guideline, and we hope to be able to grade recommendations in the future. Guidelines and recommendations for management of hypertension in pregnancy are typically written for implementation in an ideal setting. It is acknowledged that in many parts of the world, it will not be possible to adopt all of these recommendations; for this reason, options for management in less-resourced settings are discussed separately in relation to diagnosis, evaluation, and treatment. This document has been endorsed by the International Society of Obstetric Medicine and the Japanese Society for the Study of Hypertension in Pregnancy. All units managing hypertensive pregnant women should maintain and review uniform departmental management protocols and conduct regular audits of maternal and fetal outcomes. The cause(s) of preeclampsia and the optimal clinical management of the hypertensive disorders of pregnancy remain uncertain; therefore, we recommend that every hypertensive pregnant woman be offered an opportunity to participate in research, clinical trials, and follow-up studies. ### Classification 1. Hypertension in pregnancy may be chronic (predating pregnancy or diagnosed before 20 weeks of pregnancy) or de novo (either preeclampsia or gestational hypertension). 2. Chronic hypertension is associated with adverse …

1,091 citations

Journal ArticleDOI
TL;DR: The current evidence for the role of abnormal placentation and therole of placental factors such as the antiangiogenic factor, sFLT1 (soluble fms-like tyrosine kinase 1) in the pathogenesis of the maternal syndrome of preeclampsia is discussed.
Abstract: Hypertensive disorders of pregnancy-chronic hypertension, gestational hypertension, and preeclampsia-are uniquely challenging as the pathology and its therapeutic management simultaneously affect mother and fetus, sometimes putting their well-being at odds with each other. Preeclampsia, in particular, is one of the most feared complications of pregnancy. Often presenting as new-onset hypertension and proteinuria during the third trimester, preeclampsia can progress rapidly to serious complications, including death of both mother and fetus. While the cause of preeclampsia is still debated, clinical and pathological studies suggest that the placenta is central to the pathogenesis of this syndrome. In this review, we will discuss the current evidence for the role of abnormal placentation and the role of placental factors such as the antiangiogenic factor, sFLT1 (soluble fms-like tyrosine kinase 1) in the pathogenesis of the maternal syndrome of preeclampsia. We will discuss angiogenic biomarker assays for disease-risk stratification and for the development of therapeutic strategies targeting the angiogenic pathway. Finally, we will review the substantial long-term cardiovascular and metabolic risks to mothers and children associated with gestational hypertensive disorders, in particular, preterm preeclampsia, and the need for an increased focus on interventional studies during the asymptomatic phase to delay the onset of cardiovascular disease in women.

829 citations