Search results for "Ferro"
showing 10 items of 2451 documents
Off-stoichiometry in Co2FeSi thin films sputtered from stoichiometric targets revealed by nuclear magnetic resonance
2009
Co2FeSi is predicted to be a half-metallic ferromagnet with an extraordinary high magnetic moment and Curie temperature. However, a low tunnel magneto-resistance ratio, a lower spin polarization and a lower magnetic moment were experimentally observed in thin film samples. Consequently, thin Co2FeSi films of different groups were studied using spin-echo nuclear magnetic resonance (NMR). NMR probes the local hyperfine fields of the active atoms, which strongly depend on the local environment. NMR is thus able to reveal the next neighbouring shells of the Co-59 nuclei in the Co2FeSi thin films. As expected, our NMR study shows the main resonance line corresponding to Co-59 nuclei in the L2(1)…
High spin polarization in Co2CrAl–Cr superlattice
2009
The electronic structure, magnetic properties and interface effects in Co2CrAl?Cr superstructures have been investigated by the use of first principle calculations. The results show that at the interface, a large magnetic moment and a high spin polarization can be induced by a strong ferromagnetic exchange interaction at the Cr?Co interface. However, at the CrAl?Cr interface, both the magnetic moment and the spin polarization of the Cr atoms are decreased due to a Cr?Cr antiferromagnetic interaction. It can also be found that the interface effect is only a short range effect. So, high spin polarization in Co2CrAl?Cr superlattice can be obtained. Based on this theoretical analysis, a large g…
Active repair technology applied to delaminated composite structures
2009
The main target of the present paper is represented by the fracture mechanics charac-terization of delaminated composite structures actively repaired through piezoelectric patches. A boundary element code, formulated for anisotropic piezoelectric solids, including, as limiting case, the applicability to linear elastic anisotropic materials has been then imple-mented. The modeling of the delaminated composite structures as well as of the assembled structures, made of the damaged components and the patches, has been achieved through the multidomain technique. Moreover, to take into account for the adhesive layer between the host structures and the piezoelectric patches, a "spring-model" has b…
Ferrocenylbis(ylene) phosphoranes
1997
The ferrocenylbis(methylene)phosphorane Fc-P(=CTms 2 ) 2 ( 1 ) (Fc = −C 5 H 4 FeC 5 H 5 ) can be synthesized starting from ferrocenyldichlorophosphane FcPCl 2 or ferrocenyldilithiophosphane FcPLl 2 . The X-ray structure of ( 1 ) shows some unusual structural features, which indicate considerable electronic interaction of the ferrocenyl group and the σ 3 λ 5 -phosphorane unit. As a consequence of this interaction, the rotational barrier of the methylene bonds is extraordinary low. Therefore, in contrast to other bis(methylene)phosphoranes, the endo - and exo -Tms groups are indistinguishable on the NMR time scale even at −100°C. The analogous ferrocenylbis(imino)phosphorane Fc-P(=NTms) 2 ( 9…
Solitary necrotic nodules of the liver: cross-sectional imaging findings and follow-up in nine patients.
2008
OBJECTIVE. The purpose of our study was to retrospectively evaluate the sonographic, CT, and MRI findings (number, diameter, lobar location, depth from the hepatic capsule, and appearance of lesions) in a series of nine patients with pathologically proven solitary necrotic nodules of the liver and the natural evolution at follow-up in four of the nine patients.CONCLUSION. Solitary necrotic nodules are usually small, solitary lesions, mainly located under the liver capsule of the right lobe. They are hypoechoic on sonography, hypoattenuating on CT, have low signal intensity on both T1- and T2-weighted MRI with lack of enhancement after IV contrast administration, and at follow-up have a tend…
Effectiveness of lingual versus labial fixed appliances in adults according to the Peer Assessment Rating index.
2019
Introduction: The purpose of this study was to compare the effectiveness of lingual treatment and labial fixed appliances in the treatment of adult orthodontic patients. Methods: We conducted a retrospective study of 72 patients. The Peer Assessment Rating (PAR) index was measured at the start (T0) and end (T1) of treatment. Significant differences between treatment means were determined by means of analysis of variancewith the Bonferroni correction or with the use of Fisher exact test. Results: The lingual group had a mean pretreatment age of 28.6 ± 6.7 years, and the labial group had a pretreatment age of 26.6 ± 9.5 years. This difference was statistically not significant. The mean pre- a…
Identifying genetic risk variants for coronary heart disease in familial hypercholesterolemia: an extreme genetics approach
2015
Mutations in the low-density lipoprotein receptor (LDLR) gene cause familial hypercholesterolemia (FH), a disorder characterized by coronary heart disease (CHD) at young age. We aimed to apply an extreme sampling method to enhance the statistical power to identify novel genetic risk variants for CHD in individuals with FH. We selected cases and controls with an extreme contrast in CHD risk from 17 000 FH patients from the Netherlands, whose functional LDLR mutation was unequivocally established. The genome-wide association (GWA) study was performed on 249 very young FH cases with CHD and 217 old FH controls without CHD (above 65 years for males and 70 years of age for females) using the Ill…
Sequential alternating deferiprone and deferoxamine treatment compared to deferiprone monotherapy: main findings and clinical follow-up of a large mu…
2011
In β-thalassemia major (β-TM) patients, iron chelation therapy is mandatory to reduce iron overload secondary to transfusions. Recommended first line treatment is deferoxamine (DFO) from the age of 2 and second line treatment after the age of 6 is deferiprone (L1). A multicenter randomized open-label trial was designed to assess the effectiveness of long-term alternating sequential L1-DFO versus L1 alone iron chelation therapy in β-TM patients. Deferiprone 75 mg/kg 4 days/week and DFO 50 mg/kg/day for 3 days/week was compared with L1 alone 75 mg/kg 7 days/week during 5-year follow-up. A total of 213 thalassemia patients were randomized and underwent intention-to-treat analysis. Statisticall…
Resovist enhanced MR imaging of the liver: Does quantitative assessment help in focal lesion classification and characterization?
2009
Purpose: To improve characterization of focal liver lesions by a prospective quantitative analysis of percentage signal intensity change, in dynamic and late phases after slow (0.5 mL/s) Resovist administration. Materials and Methods: Seventy-three patients were submitted on clinical indication to MR examination with Resovist. Signal intensity of 92 detected focal lesions (5–80 mm) were measured with regions of interest and normalized to paravertebral muscle in arterial, portal, equilibrium and T1/T2 late phases, by two observers in conference. Five values of percentage variations per patient were obtained and statistically evaluated. Results: The enhancement obtained on dynamic study is mo…
Association between xerostomia, oral and general health, and obesity in adults. A cross-sectional pilot study.
2021
Background The objective of this study was to analyse the association between oral and general health variables and obesity indicators with the sensation of dry mouth or xerostomia as evaluated on the Xerostomia Inventory (XI). Material and Methods A total of 354 randomly selected subjects participated in this cross-sectional pilot study and completed an anonymous questionnaire. Anthropometric, clinical, and xerostomic variables were evaluated. Kruskal-Wallis, ANOVA and Bonferroni test were used for multiple comparisons. ROC curves and multinomial logistic regression were used to determine the (OR) risk of xerostomia. Results A total of 30.7 % of respondents reported xerostomia based on XI.…