Search results for "exaf"
showing 10 items of 822 documents
Corrosion and wear resistance of coatings produced on AZ31 Mg alloy by plasma electrolytic oxidation in silicate-based K2TiF6 containing solution: Ef…
2022
Abstract In this research, plasma electrolytic oxidation coatings were prepared on AZ31 Mg alloy in a silicate-based solution containing K2TiF6 using bipolar and soft sparking waveforms with 10, 20, and 30% cathodic duty cycles. The coatings displayed a net-like surface morphology consisted of irregular micro-pores, micro-cracks, fused oxide particles, and a sintered structure. Due to the incorporation of TiO2 colloidal particles and the cathodic pulse repair effect, most of the micro-pores were sealed. Long-term corrosion performance of the coatings was investigated using electrochemical impedance spectroscopy during immersion in 3.5 wt.% NaCl solution up to 14 days. The coating grown by t…
Absorption spectrum of the and electronic transitions of ReF6
1999
Abstract The absorption spectra of the near-infrared and ultraviolet bands of ReF6 have been recorded with a commercial spectrophotometer. The vibronic assignments previously published by different authors are critically revised. A non-perturbative method has been used to calculate the linear Jahn–Teller levels for the ν5 mode in the ground electronic state. Some new vibronic parameter values are derived. The ν5 linear Jahn–Teller parameter in the X G′ g electronic state is found to be D5=0.103(9). The ultraviolet absorption spectrum has enabled us to determine relatively accurate values of the crystal-field (10Dq) and spin-orbit (ζd) parameters.
Analysis of the U L3-edge X-ray absorption spectra in UO2 using molecular dynamics simulations
2017
This work was supported by a grant from the Swiss National Supercomputing Centre (CSCS) under the project ID s444. The resource allocation within the PSI share at CSCS and on the PSI compute cluster Merlin4 is also acknowledged. D. B. is grateful for a fellowship within the Sciex-NMS programme. A. K. was supported by Latvian Science Council Grant no. 187/2012.
Contrast-Enhanced Ultrasonography With SonoVue
2009
Objective. We investigated the ability of contrast-enhanced ultrasonography with SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal splenic lesions. Methods. In a prospective study we investigated 35 lesions in 35 patients (24 male and 11 female; mean age ± SD, 54 ± 15 years) with focal splenic lesions detected by B-mode ultrasonography. After intravenous injection of 1.2 to 2.4 mL of SonoVue, the spleen was examined continuously for 3 minutes using low–mechanical index ultrasonography with contrastspecific software. The final diagnosis was established by histologic examination, computed tomography, …
Characterization of hypoechoic focal hepatic lesions in patients with fatty liver: diagnostic performance and confidence of contrast-enhanced ultraso…
2007
The objective of this study was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) to characterize hypoechoic focal hepatic lesions (HFHL) in fatty liver (FL). A study group of 105 patients with FL and 105 HFHLs (52 malignant and 53 benign) underwent CEUS after SonoVue administration. Two blinded readers independently reviewed baseline ultrasound (US) and CEUS scans and classified each lesion as malignant or benign on a five-point scale of confidence, and recorded whether further imaging work-up was needed. Sensitivity, specificity, areas under the receiver operating characteristic (ROC) curve (A (z)), and interobserver agreement were calculated. We observed that th…
Hepatic focal nodular hyperplasia: contrast-enhanced ultrasound findings with emphasis on lesion size, depth and liver echogenicity
2010
To correlate contrast-enhanced ultrasound (CEUS) findings of hepatic focal nodular hyperplasia (FNH) with lesion size, depth and liver echogenicity and to compare CEUS with baseline US. Two radiologists evaluated baseline US and CEUS examinations of 92 FNHs (mean size: 3.1 +/- 1.7 cm) in 71 patients (59 women and 12 men) to detect the "spoke-wheel" sign, central scar and feeding vessel. The FNHs were grouped and analysed by dimension, depth and liver echogenicity. At least one sign could be detected at CEUS in 27 out of 36 (75%) FNHs larger than 3 cm and in 17 out of 56 (30%) FNH measuring 3 cm or less (p 0.05) as well as between CEUS or baseline US/CD with regard to lesion size, depth or l…
Indeterminate focal liver lesions incidentally discovered at gray-scale US: role of contrast-enhanced sonography.
2011
OBJECTIVES: to assess the role of contrast-enhanced ultrasound (CEUS) in the characterization of focal liver lesions (FLLs) incidentally discovered but indeterminate at gray-scale ultrasound (US). MATERIALS AND METHODS: one hundred forty-two consecutive patients with 174 FLLs (169 benign and 5 malignant) incidentally discovered but indeterminate at gray-scale US, underwent CEUS after the administration of SonoVue. Two readers independently reviewed CEUS scans and: (1) classified each lesion as malignant or benign on a 5-point scale of confidence by means of definite diagnostic criteria; (2) provided if possible a specific diagnosis; (3) were requested if further imaging was needed for lesio…
Study of neurinomas with ultrasound contrast media: review of a case series to identify characteristic imaging patterns
2011
The aim of this study was to evaluate whether there exists a characteristic distribution pattern of vessels within neurinomas that may be used to characterise this type of lesion by employing a contrast-specific ultrasound technique.Between January 2003 and May 2010, 66 suspected neurinomas were evaluated according to their sonographic features (solid fusiform mass with well-defined margins located in direct continuity with the nerve that was not always discernible and heterogeneous as a result of the presence of small cystic areas or calcifications). The lesions were examined using a sonographic contrast medium consisting of sulphur hexafluoride microbubbles and equipment with dedicated co…
Contrast-enhanced ultrasonography: usefulness in the assessment of postoperative recurrence of Crohn's disease.
2013
Abstract Aim The aim of this study was to assess whether the contrast-enhanced ultrasonography (CEUS) can increase the value of the ultrasonography in the study of postoperative recurrence of Crohn's disease (CD). Materials and methods 60 patients with CD who had previously undergone ileocolic resection underwent prospectively both CEUS and colonoscopy within a 3-day period. The sonographic examination included evaluation of bowel wall thickness, transmural complications, colour Doppler grade and contrast-enhanced US. In addition a sonographic score was established. The capacity of CEUS to diagnose endoscopic recurrence, as well as its severity, was assessed by calculating the sensitivity, …
Evaluation of posttreatment response of hepatocellular carcinoma: comparison of ultrasonography with second-generation ultrasound contrast agent and …
2010
We evaluated the ability of one-month follow-up contrast-enhanced ultrasound (CEUS) with second-generation contrast agent in monitoring radio frequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) treatments of hepatocellular carcinoma (HCC). One-hundred forty-eight HCCs were studied using CEUS: 110 nodules were treated with RFA [41/110 RFA were performed using a pretreatment and an immediate postablation evaluation using CEUS (group 1); 69/110 using only US guidance (group 2)] and 38 nodules treated with TACE. For statistical analysis, McNemar test was used. Overall complete response was observed in 107/148 nodules (92/110 treated with RFA and 15/38 with TACE). A bett…