Valence and magnetic instabilities in Sm compounds at high pressures

We report on the study of the response to high pressures of the electronic and magnetic properties of several Sm-based compounds, which span at ambient pressure the whole range of stable charge states between the divalent and the trivalent. Our nuclear forward scattering of synchrotron radiation and specific heat investigations show that in both golden SmS and SmB6 the pressure-induced insulator to metal transitions (at 2 and about 4-7 GPa, respectively) are associated with the onset of long-range magnetic order, stable up to at least 19 and 26 GPa, respectively. This long-range magnetic order, which is characteristic of Sm(3+), appears already for a Sm valence near 2.7. Contrary to these compounds, metallic Sm, which is trivalent at ambient pressure, undergoes a series of pressure-induced structural phase transitions which are associated with a progressive decrease of the ordered 4f moment.Comment: 15 pages (including 7 figures) submitted to J. Phys.: Condens. Matte

Double-spiral magnetic structure of the Fe/Cr multilayer revealed by nuclear resonance scattering

We have studied the magnetization depth profiles in a [57Fe(dFe)/Cr(dCr)]x30 multilayer with ultrathin Fe layers and nominal thickness of the chromium spacers dCr 2.0 nm using nuclear resonance scattering of synchrotron radiation. The presence of a broad pure-magnetic half-order (1/2) Bragg reflection has been detected at zero external field. The joint fit of the reflectivity curves and Mossbauer spectra of reflectivity measured near the critical angle and at the "magnetic" peak reveals that the magnetic structure of the multilayer is formed by two spirals, one in the odd and another one in the even iron layers, with the opposite signs of rotation. The double-spiral structure starts from the surface with the almost antiferromagnetic alignment of the adjacent Fe layers. The rotation of the two spirals leads to nearly ferromagnetic alignment of the two magnetic subsystems at some depth, where the sudden turn of the magnetic vectors by ~180 deg (spin-flop) appears, and both spirals start to rotate in opposite directions. The observation of this unusual double-spiral magnetic structure suggests that the unique properties of giant magneto-resistance devices can be further tailored using ultrathin magnetic layers.Comment: 9 pages, 3 figure

Fernando de Azevedo e a Educação Física: suas contribuições para a constituição do campo a partir do Manifesto dos Pioneiros da Escola Nova de 1932

Resumo: A presente pesquisa apresenta uma discussão em torno de quais seriam as contribuições do reformador educacional Fernando de Azevedo, para a constituição do campo da Educação Física a partir do Manifesto dos Pioneiros da Escola Nova de 1932. Nesse sentido, o objetivo principal desse trabalho é desvelar as contribuições de Fernando de Azevedo para a constituição do campo da Educação Física no Brasil, a partir do Manifesto dos Pioneiros da Escola Nova de 1932. Para atingir esse objetivo, foram utilizadas como fontes primárias Castellani Filho (1988) e Soares (2004), além de fontes secundárias, necessárias ao enriquecimento das reflexões aqui apresentadas. A pesquisa do tipo estado do conhecimento foi desenvolvida a partir de uma perspectiva exploratória e descritiva, de natureza qualitativa, que se utiliza dos descritores, Educação Física e Fernando de Azevedo. Foi possível concluir que Fernando de Azevedo tem suas contribuições para a constituição do campo da Educação Física, todavia, muito do que promulgava nos seus escritos e nas reformas educacionais não se aplica na atualidade.

Cytotoxic activity of proteins isolated from extracts of Corydalis cava tubers in human cervical carcinoma HeLa cells

<p>Abstract</p> <p>Background</p> <p><it>Corydalis cava </it>Schweigg. & Koerte, the plant of numerous pharmacological activities, together with the studied earlier by our group <it>Chelidonium majus </it>L. (Greater Celandine), belong to the family <it>Papaveraceae</it>. The plant grows in Central and South Europe and produces the sizeable subterraneous tubers, empty inside, which are extremely resistant to various pathogen attacks. The <it>Corydalis sp. </it>tubers are a rich source of many biologically active substances, with the extensive use in European and Asian folk medicine. They have analgetic, sedating, narcotic, anti-inflammatory, anti-allergic and anti-tumour activities. On the other hand, there is no information about possible biological activities of proteins contained in <it>Corydalis cava </it>tubers.</p> <p>Methods</p> <p>Nucleolytic proteins were isolated from the tubers of <it>C. cava </it>by separation on a heparin column and tested for DNase activity. Protein fractions showing nucleolytic activity were tested for cytotoxic activity in human cervical carcinoma HeLa cells. Cultures of HeLa cells were conducted in the presence of three protein concentrations: 42, 83 and 167 ng/ml during 48 h. Viability of cell cultures was appraised using XTT colorimetric test. Protein fractions were separated and protein bands were excised and sent for identification by mass spectrometry (LC-ESI-MS/MS).</p> <p>Results</p> <p>The studied protein fractions showed an inhibiting effect on mitochondrial activity of HeLa cells, depending on the administered dose of proteins. The most pronounced effect was obtained with the highest concentration of the protein (167 ng/ml) - 43.45 ± 3% mitochondrial activity of HeLa cells were inhibited. Mass spectrometry results for the proteins of applied fractions showed that they contained plant defense- and pathogenesis-related (PR) proteins.</p> <p>Conclusions</p> <p>The cytotoxic effect of studied proteins toward HeLa cell line cells has been evident and dependent on increasing dose of the protein. The present study, most probably, represents the first investigations on the effect of purified PR proteins from tuber extracts of a pharmacologically active plant on cell lines.</p

Faecal lactoferrin, calprotectin, pmn-elastase, crp, and white blood cell count as indicators for mucosal healing and clinical course of disease in patients with mild to moderate ulcerative colitis: Post hoc analysis of a prospective clinical trial

© 2016 European Crohn's and Colitis Organisation (ECCO). Objectives: We evaluated the performance of blood and faecal biomarkers for differentiating between endoscopic inflammation and mucosal healing, and clinically active disease and sustained clinical remission, and determined the predictive value for a flare in patients with ulcerative colitis [UC]. Methods: Clinical Activity Index [CAI], faecal lactoferrin [FLA], calprotectin [CAL], PMN-elastase [PMN-e], C-reactive protein [CRP], white blood cells [WBC], Endoscopic Index [EI], and UC-Disease Activity Index [DAI] were determined repeatedly during 12 months and at acute flares. Results: Of 91 patients [45 female; mean age 48.1 ± 13.4 years] entering in remission, 42 [46%] patients developed a clinical flare. A total of 529 CAI and 179 EI assessments were performed. Median levels for active disease confirmed by EI [n = 35] vs clinical remission with endoscopic inflammation [n = 37] vs mucosal healing [n = 107] for FLA were 44/37/4 μg/g, CAL 25/20/10 μg/g [both p < 0.0001], PMN-e 0.06/0.03/0.02 μg/g, CRP 0.7/0.2/0.2 mg/dl [both p < 0.001], and WBC 7.0/6.5/6.4/nl [p = 0.1]. There was no difference for any of the markers for defining mucosal healing by EI = 0 vs EI = 1 with the exception of PMN-e [p = 0.03], where the difference was very small and with questionable clinical relevance. Using manufacturers' cut-offs, only FLA at baseline was associated with a significant higher relative risk [RR] of flaring [RR 1.69; p = 0.018]. Using optimised cut-offs, CAL, PMN-e, and CRP were also predictive of a flare. Conclusions: Faecal biomarkers FLA, CAL, and PMN-e were able to distinguish between UC patients with mucosal healing from clinical remission and mild disease, showed significant correlations with endoscopy, and were predictive of a flare