16 research outputs found

    Magnetic Properties of NdFe0.9Mn0.1O3

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    In our paper we study effect of Mn for Fe substitution on magnetic properties of NdFex-1MnxO3 compounds for x = 0 and 0.1, which have been grown by the OFZ technique. The Neel temperature decreases from T-N1 = 691 K to T-N1 = 621 K, and the anomaly in AC susceptibility, related to spin reorientation, vanishes with Mn substitution. Low temperature heat capacity measurement for sample with x = 0.1 revealed that substitution of Mn for Fe shifts a Schottky-type anomaly at T-sh to higher temperatures. Another anomaly is generated by doping at T-max = 11 K. The anomaly is smeared out by magnetic field, confirming its magnetic origin.15th Czech and Slovak Conference on Magnetism (CSMAG), Jun 17-21, 2013, Kosice, Slovaki

    Exchange Bias Effect in NdFeO3 System of Nanoparticles

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    We study the effect of nanometric size on the crystal structure, magnetic environment of iron and magnetization in NdFeO3 system of nanoparticles. The average particle size of NdFeO3 nanoparticles increases with annealing at 600 degrees C from about 15 nm to 40 nm, The smallest particles on annealed sample have size approximately 30 nm and typically have character of single crystalline samples. All samples adopt orthorhombic crystal structure, space group Prima with lattice parameters a = 5.5817 angstrom, b = 7.7663 angstrom and c = 5.456 angstrom for as prepared sample. The presence of superparamagnetic particles was indicated by the Mossbauer measurements. The reduction of dimensionality induces a decrease of T-N1 from 691 K to 544 K. The shift of magnetic hysteresis loop in vertical and horizontal direction was observed at low temperatures after cooling in magnetic field. We attribute such behaviour to exchange bias effect and discuss in the frame of core shellmodel.16th Czech and Slovak Conference on Magnetism (CSMAG), Jun 13-17, 2016, Kosice, Slovaki

    Magnetic Properties and Mossbauer spectroscopy of NdFe(1-x)MnxO(3)

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    The effect of particle reduction to nanoscale size and substitution of Mn3+ ions for Fe3+ ions on the crystal structure, lattice dynamics, Mossbauer spectra and magnetic properties in NdFe(1-x)MnxO(3) compounds have been studied. X-ray powder diffraction and Raman spectroscopy revealed that the Jahn-Teller distortion of lattice dominates for samples with x GT 0.4. The average particle size of NdFeO3 nanoparticles (NAP) increases with annealing at 600 degrees C from about 15 nm to 25 nm. The presence of superparamagnetic particles was indicated by Mossbauer measurements in NdFeO3 NAP system. Sextets in NdFe(1-x)MnxO(3) Mssbauer spectra can be modelled with several local environments of Fe3+ induced by substitution. The reduction of dimensionality and the substitution induce a decrease of the Neel temperature T-Nl from 691 K to 544 K for NAP or to 356 K for x = 0.4, however the temperature of spin reorientation T-SR increases with substitution. The saturated magnetization obtained at 1.9 K increases and ferromagnetic component is removed below T-SR with the substitution.International Conference on Strongly Correlated Electron Systems (SCES), Jul 07-14, 2014, Univ Grenoble, Grenoble, Franc

    Characteristics of specialists treating hypothyroid patients: the “THESIS” collaborative

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    Copyright \ua9 2023 Žarković, Attanasio, Nagy, Negro, Papini, Perros, Cohen, Akarsu, Alevizaki, Ayvaz, Bednarczuk, Berta, Bodor, Borissova, Boyanov, Buffet, Burlacu, Ćirić, D\uedez, Dobnig, Fadeyev, Field, Fliers, Fr\uf8lich, F\ufchrer, Galofr\ue9, Hakala, Jiskra, Kopp, Krebs, Kršek, Kužma, Lantz, Laz\ufarov\ue1, Leenhardt, Luchytskiy, McGowan, Melo, Metso, Moran, Morgunova, Mykola, Beleslin, Niculescu, Perić, Planck, Poiana, Puga, Robenshtok, Rosselet, Ruchala, Riis, Shepelkevich, Unuane, Vardarli, Visser, Vrionidou, Younes, Yurenya and Heged\ufcs.Introduction: Thyroid specialists influence how hypothyroid patients are treated, including patients managed in primary care. Given that physician characteristics influence patient care, this study aimed to explore thyroid specialist profiles and associations with geo-economic factors. Methods: Thyroid specialists from 28 countries were invited to respond to a questionnaire, Treatment of Hypothyroidism in Europe by Specialists: an International Survey (THESIS). Geographic regions were defined according to the United Nations Statistics Division. The national economic status was estimated using World Bank data on the gross national income per capita (GNI per capita). Results: 5,695 valid responses were received (response rate 33\ub70%). The mean age was 49 years, and 65\ub70% were female. The proportion of female respondents was lowest in Northern (45\ub76%) and highest in Eastern Europe (77\ub72%) (p <0\ub7001). Respondent work volume, university affiliation and private practice differed significantly between countries (p<0\ub7001). Age and GNI per capita were correlated inversely with the proportion of female respondents (p<0\ub701). GNI per capita was inversely related to the proportion of respondents working exclusively in private practice (p<0\ub7011) and the proportion of respondents who treated >100 patients annually (p<0\ub701). Discussion: THESIS has demonstrated differences in characteristics of thyroid specialists at national and regional levels, strongly associated with GNI per capita. Hypothyroid patients in middle-income countries are more likely to encounter female thyroid specialists working in private practice, with a high workload, compared to high-income countries. Whether these differences influence the quality of care and patient satisfaction is unknown, but merits further study

    Social support and psychological distress in rheumatoid arthritis: a 4-year prospective study

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    Introduction: The objective of the study was to investigate the course of psychological distress in early rheumatoid arthritis patients and to explore the strength of its associations with disease-related variables over time. A further aim focused specifically on the associations between social support and psychological distress. Methods: The study had a longitudinal design, with four annual measurements over consecutive years. The course and stability of psychological distress on the individual level were investigated via test-retest correlation coefficients and changes over time were studied using the Friedman test for repeated measurements. Hierarchical regression analysis was performed to analyze the multilinear associations of disease activity, functional disability, joint tenderness, pain and social support with psychological distress. Results: Significant cross-sectional associations were found among functional disability, joint tenderness, pain, emotional support, instrumental support and psychological distress. However, after controlling for the erratic pattern of the disease and the relevant variables, only initial psychological distress and emotional support retained a significant relationship with psychological distress. The final regression model, in which functional disability, pain, emotional support and initial psychological distress were significant variables, explained 36% of the variance in psychological distress. Conclusion: The study stresses the importance of initial psychological distress, which was found to have the highest correlation with psychological distress experienced 4 years later. In addition, higher emotional support and lower pain were found to be the only variables independently associated with lower levels of psychological distress after controlling for the relevant variables. [Box: see text]

    Exchange Bias Effect in NdFeO_3 System of Nanoparticles

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    We study the effect of nanometric size on the crystal structure, magnetic environment of iron and magnetization in NdFeO3 system of nanoparticles. The average particle size of NdFeO3 nanoparticles increases with annealing at 600 degrees C from about 15 nm to 40 nm, The smallest particles on annealed sample have size approximately 30 nm and typically have character of single crystalline samples. All samples adopt orthorhombic crystal structure, space group Prima with lattice parameters a = 5.5817 angstrom, b = 7.7663 angstrom and c = 5.456 angstrom for as prepared sample. The presence of superparamagnetic particles was indicated by the Mossbauer measurements. The reduction of dimensionality induces a decrease of T-N1 from 691 K to 544 K. The shift of magnetic hysteresis loop in vertical and horizontal direction was observed at low temperatures after cooling in magnetic field. We attribute such behaviour to exchange bias effect and discuss in the frame of core shellmodel.16th Czech and Slovak Conference on Magnetism (CSMAG), Jun 13-17, 2016, Kosice, Slovaki

    Role of positron emission tomography and bone scintigraphy in the evaluation of bone involvement in metastatic pheochromocytoma and paraganglioma: specific implications for succinate dehydrogenase enzyme subunit B gene mutations.

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    Contains fulltext : 71093timmers.pdf (publisher's version ) (Closed access)We performed a retrospective analysis of 71 subjects with metastatic pheochromocytoma and paraganglioma (30 subjects with mutation of succinate dehydrogenase enzyme subunit B (SDHB) gene and 41 subjects without SDHB mutation). Sixty-nine percent presented with bone metastases (SDHB +/-: 77% vs 63%), 39% with liver metastases (SDHB +/-: 27% vs 47%), and 32% with lung metastases (SDHB +/-: 37% vs 29%). The most common sites of bone involvement were thoracic spine (80%; SDHB+/-: 83% vs 77%), lumbar spine (78%; SDHB +/-: 78% vs 75%), and pelvic and sacral bones (78%; SDHB +/-: 91% vs 65%, P=0.04). Subjects with SDHB mutation also showed significantly higher involvement of long bones (SDHB +/-: 78% vs 30%, P=0.007) than those without the mutation. The best overall sensitivity in detecting bone metastases demonstrated positron emission tomography (PET) with 6-[(18)F]-fluorodopamine ([(18)F]-FDA; 90%), followed by bone scintigraphy (82%), computed tomography or magnetic resonance imaging (CT/MRI; 78%), 2-[(18)F]-fluoro-2-deoxy-d-glucose ([(18)F]-FDG) PET (76%), and scintigraphy with [(123/131)I]-metaiodobenzylguanidine (71%). In subjects with SDHB mutation, imaging modalities with best sensitivities for detecting bone metastases were CT/MRI (96%), bone scintigraphy (95%), and [(18)F]-FDG PET (92%). In subjects without SDHB mutations, the modality with the best sensitivity for bone metastases was [(18)F]-FDA PET (100%). In conclusion, bone scintigraphy should be used in the staging of patients with malignant pheochromocytoma and paraganglioma, particularly in patients with SDHB mutations. As for PET imaging, [(18)F]-FDG PET is highly recommended in SDHB mutation patients, whereas [(18)F]-FDA PET is recommended in patients without the mutation

    Obesity management in women with polycystic ovary syndrome

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    Copyright © 2007 Future MedicineObesity and insulin resistance play an important role in initiating or maintaining ill health in polycystic ovary syndrome (PCOS). This implies that treatment that reduces body weight and insulin resistance would alleviate the symptoms of PCOS. Lifestyle modification has been found to be effective in restoring reproductive function in up to 80% of individuals who achieve at least 5% weight loss. However, long-term weight maintenance is a challenge. This article provides a review of reduced glycemic load diets, including low glycemic index, very low carbohydrate, high-protein and high monounsaturated fat diets, on metabolic and reproductive health in PCOS and non-PCOS populations. Dietary trials in non-PCOS women suggest that higher-protein, reduced glycemic load diets were probably more beneficial than the conventional low-fat, high-carbohydrate diet but further studies are required to confirm this in PCOS women. Similarly, the optimal exercise regime for PCOS women remains to be investigated.Siew S Lim, Peter M Clifton, Manny Noakes & Robert J Norma
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