Design and Development of a Tunable Ferroelectric Microwave Surface Mounted Device.

Based on a Ba(1-x)SrxTiO3 ferroelectric thin film, a discrete tunable surface mounted device (SMD) capacitor has been developed for microwave frequency applications. The proposed SMD topology has the particular advantage of inherent decoupling between the RF signal and the dc biasing voltage, necessary to tune the ferroelectric permittivity. The design and technological development of the SMD component is presented, and the synthesis of the ferroelectric thin film is summarized. Material characterization shows convenient tunability, while low dielectric losses at 10 MHz. The integration of the SMD tunable capacitor into a Planar Inverted-F Antenna has been done in order to evaluate the agility and tunability performance of the antenna.

Domain wall motion in Pb(Zr0.20Ti0.80)O3 epitaxial thin films.

Two Pb(Zr0.20Ti0.80)O3 samples of different thickness and domain configuration have been studied. The c-domain sample was found to have a higher coercive field E c and higher dielectric losses than the other which presents approximately 60% of c-domains and 40% of a-domains as observed by piezo force microscopy (PFM) characterization. Hyperbolic law measurements reveal that the higher coercive field is due to domain wall pinning in deeper defects and hence a higher field E th is required for unpinning. The dissipation factors due to domain wall motion, however, are similar in both samples since the domain wall density is low and there is almost no interaction between domain walls. The higher dielectric losses in the c-domain oriented sample are a result of a greater contribution from the lattice and seem to be due to strain from the substrate, which is not relieved in a thin sample. PFM and dielectric characterization are complementary methods which provide a better understanding of the domain wall motion.

[Does prenatal diagnosis modify neonatal management and early outcome of children with esophageal atresia type III?]. / Le diagnostic anténatal modifie-t-il la prise en charge néonatale et le devenir à 1 an des enfants suivis pour atrésie de l'œsophage de type III ?

OBJECTIVE: Evaluate neonatal management and outcome of neonates with either a prenatal or a post-natal diagnosis of EA type III. STUDY DESIGN: Population-based study using data from the French National Register for EA from 2008 to 2010. We compared children with prenatal versus post-natal diagnosis in regards to prenatal, maternal and neonatal characteristics. We define a composite variable of morbidity (anastomotic esophageal leaks, recurrent fistula, stenosis) and mortality at 1 year. RESULTS: Four hundred and eight live births with EA type III were recorded with a prenatal diagnosis rate of 18.1%. Transfer after birth was lower in prenatal subset (32.4% versus 81.5%, P<0.001). Delay between birth and first intervention was not significantly different. Defect size (2cm vs 1.4cm, P<0.001), gastrostomy (21.6% versus 8.7%, P<0.001) and length in neonatal unit care were higher in prenatal subset (47.9 days versus 33.6 days, P<0.001). The composite variables were higher in prenatal diagnosis subset (38.7% vs 26.1%, P=0.044). CONCLUSION: Despite the excellent survival rate of EA, cases with antenatal detection have a higher morbidity related to the EA type (longer gap). Even if it does not modify neonatal management and 1-year outcome, prenatal diagnosis allows antenatal parental counseling and avoids post-natal transfer.

Diffusion-weighted magnetic resonance imaging in ileocolonic Crohn's disease: validation of quantitative index of activity.

OBJECTIVES: Magnetic resonance imaging (MRI) allows accurate assessment of Crohn's disease (CD), but requires gadolinium injection. Diffusion-weighted (DW)-MRI yields comparable performances in small bowel CD. We compared the accuracy of DW-MR enterocolonography (MREC) and the magnetic resonance index of activity (MaRIA), and performed an external validation of the Clermont score in assessing inflammation in CD. METHODS: This was an observational prospective study of a single-center cohort. A total of 130 CD patients underwent consecutively MREC with gadolinium injection and DWI sequences between July 2011 and December 2012. RESULTS: Of the 848 evaluated segments (small bowel=352, colon/rectum=496), 175 (20.6%) were active (small bowel=111, colon/rectum=64) defined as MaRIA ≥7. Using a receiver operating characteristic (ROC) curve, we determined an apparent coefficient of diffusion (ADC) threshold of 1.9 × 10(-3) mm(2)/s that yielded a sensitivity and a specificity in discriminating active from nonactive CD of 96.9% and 98.1%, respectively, for the colon/rectum, and 85.9% and 81.6%, respectively, for the ileum. ADC was better correlated to MaRIA ≥7 than related contrast enhancement obtained with injected sequences (P<0.001). The Clermont score (=1.646 × bowel thickness-1.321 × ADC+5.613 × edema+8.306 × ulceration+5.039) was highly correlated with the MaRIA (rho=0.99) in ileal CD but not in colonic CD (rho <0.80). Interobserver agreement was high with regard to ADC measurement (correlation >0.9, P<0.001, and concordance >0.9, P<0001). CONCLUSIONS: DW-MREC is a reliable tool to assess inflammation in colonic (ADC) and ileal (Clermont score) CD and its use in daily practice would avoid gadolinium injection.

[Sudden unexpected death in an infant due to a ruptured coronary aneurysm revealing Kawasaki disease]. / Mort subite chez un nourrisson par rupture d'anévrisme coronarien révélatrice d'une maladie de Kawasaki.

UNLABELLED: The early mortality of Kawasaki disease is low, resulting from coronary complications, mainly aneurismal thrombosis with myocardial infarction. The aneurysmal rupture is an exceptional cause of death. CASE REPORT: We report on a six-month-old girl who died suddenly and unexpectedly. The autopsy showed a cardiac tamponade caused by an important ruptured aneurysm of the left coronary artery. Multiple aneurysms, with or without thrombosis, on the right coronary were also present. There was no ischaemic lesion. Three weeks before death, this infant demonstrated several clinical signs of Kawasaki disease whose diagnosis had not been done. CONCLUSION: Even if the rupture of coronary aneurysm is an exceptional initial complication of Kawasaki disease, a better knowledge of the atypical or incomplete forms, particularly below the age of one year, should allow an early diagnosis and treatment, decreasing the risks of coronary complications. This observation furthermore illustrates the interest of post-mortem examination in all sudden or unexpected infant deaths.

Johanson-Blizzard syndrome. a new case with autopsy findings.

Here we present a new case of Johanson-Blizzard Syndrome. Clinical features consistent with the diagnosis of Johanson-Blizzard Syndrome in a term neonate are described: intra-uterine growth retardation, aplasia of the nasal alae, midline scalp defect, total situs inversus, imperforate anus, malrotation of the small intestine, pancreatic insufficiency, deafness, and lethal congenital heart defects with dextrocardia. These features were confirmed by findings at autopsy. Parents were consanguineous. We compare these clinical features and findings at autopsy with previous cases reported in the literature.