Structure and piezo-ferroelectricity relationship study of (K0.5Na0.5)0.985La0.005NbO3 epitaxial films deposited on SrTiO3 by sputtering.

This work demonstrates that the rf-sputtering technique, combined with appropriate heat treatments, is potentially effective to develop new materials and devices based on oxide-interface and strain engineering. We report a study of the structural-physical properties relationship of high crystalline quality, highly oriented and epitaxial thin films of the lead-free (K0.5Na0.5)0.985La0.005NbO3 (KNNLa) compound which were successfully deposited on Nb-doped SrTiO3 substrates, with orientations [100] (NSTO100) and [110] (NSTO110). The crystalline growth and the local ferroelectric and piezoelectric properties were evaluated by piezoresponse force microscopy combined with transmission electron microscopy and texture analysis by X-ray diffraction. Conditioned by the STO surface parameters, in the KNNLa films on NSTO100 coexist a commensurate [001]-tetragonal phase and two incommensurate [010]-monoclinic phases; while on NSTO110 the KNNLa films grew only in an incommensurate [101]-monoclinic phase. Both samples show excellent out-of-plane polarization switching patterns consistent with 180° domains walls; while for KNNLa/NSTO100 ferroelectric domains grow with the polarization pointing down, for KNNLa/NSTO110 they prefer to grow with the polarization pointing up. Comparing with previous reports on epitaxial KNN films, we find our samples to be of very high quality regarding their crystalline growth with highly ordered ferroelectric domains arrangements and, consequently, great potential for domain engineering.

Aortoenteric fistula after endovascular abdominal aortic aneurysm treatment with the original Gore Excluder endoprosthesis and Cook aortouniiliac converter for endotension.

We report a case of aortoenteric fistula (AEF) that occurred four years after endovascular abdominal aortic aneurysm repair (EVAR) with the original Gore Excluder endoprosthesis despite uncomplicated stent graft placement without endoleaks or migration on postoperative imaging studies; the patient was reoperated with a Cook aortouniiliac converter for endotension three months before the diagnosis of AEF. To our knowledge, this is the first reported case in the literature of an AEF after EVAR with the Excluder stent graft. Our case demonstrates that EVAR is not a guarantee against the development of AEF, and we suggest that all the patients with the first generation Excluder device should be closely followed-up; if sac enlargement is detected, early conversion to open repair or reinforcement of the entire old endograft should be considered.

Direct association between C-reactive protein serum levels and endothelial dysfunction in patients with claudication.

OBJECTIVES: To evaluate the relationship between C-Reactive Protein (hsCRP), a serum marker of inflammation, and endothelial dysfunction in patients with intermittent claudication. DESIGN, PATIENTS AND METHODS: Cross-sectional study with stratified sampling on dependent variables of age, genre, hypertension, hyperlipidemia, diabetes, smoking status and ankle-brachial index (ABI) to select 156 patients from a target population of 4,100 patients with claudication. We assessed the flow-mediated arterial dilation (FMAD) as a reporter of endothelial function and plasma levels of hsCRP and fibrinogen. RESULTS: Patients with a FMAD<3% (range for the lowest 5% of healthy subjects) had increased levels of plasma hsCRP (6.3 vs 2.3mg/L; p<0.05) and fibrinogen (351vs 302mg/L; p<0.05) in comparison to those with FMAD>3%. There was a negative correlation between hsCRP and FMAD(r=-0.465; p<0.05). CONCLUSION: Impaired endothelial dysfunction is association with increased plasma concentrations of inflammatory markers, and both may have a role in the aetiopathogenesis of peripheral arterial disease.