Adipocyte size in morbidly obese women and its relation to type 2 diabetes

Aim of the study: The aim was to perform a morphometric analysis of subcutaneous and visceral adipose tissue of morbidly obese women and to determine the relationship between adipocyte size and the development of type 2 diabetes (T2D)

Collapse of ferromagnetism in itinerant-electron system: A magnetic, transport properties, and high pressure study of (Hf,Ta)Fe2 compounds

International audienc

Pressure-induced changes in the structural and magnetic properties of YFe2D4.2

International audienceThe study of the structural and magnetic properties of YFe2D4.2 under high pressure has been performed by combining energy dispersive x-ray diffraction at room temperature up to 5.5 GPa, neutron diffraction studies at low temperature up to 2.5 GPa, and magnetization measurements up to 1 GPa. The monoclinic structure of YFe2D4.2 at ambient temperature and pressure is related to a distortion of the initial cubic C15 structure of YFe2 by the ordering of inserted D atoms. A structural transition from monoclinic to cubic structure is observed at 4 GPa. The high pressure cubic YFe2D4.2 has a 19% higher cell volume than that of YFe2. The application of an external pressure leads to the progressive decrease of the transition temperature TM0 from ferro to antiferromagnetic order (TM0 = 84 K at ambient pressure) and even to the suppression of the ferromagnetic ground state for pressures larger than 0.54 GPa. Moreover using the compressibility value determined by x-ray diffraction (κ = 0.013 GPa-1), the decrease of volume at the critical pressure of 0.54 GPa (0.70%) is in very good agreement with the increase of volume observed at the transition from antiferromagnetic to ferromagnetic state at ambient pressure (0.65%), indicating the crucial role of volume effect. An antiferromagnetic structure was detected between TM0 and TN and for pressures larger than 0.54 GPa in the whole temperature range below TN. In addition, a large pressure effect on the spontaneous magnetization MS for pressures below 0.4 GPa, d ln MS/d P = -7.3 × 10-2 GPa-1 was discovered. This clearly proves the delocalized character of the iron 3d band magnetism in YFe2D4.2 compound. The pressure evolution of the magnetic phase diagram of YFe2D4.2 has been determined

Effect of pressure on the electrical resistivity and magnetism in UPdSn

The electrical resistivity of a UPdSn single crystal exerted to various hydrostatic pressures was measured as a function of temperature and magnetic field. Clear anomalies in the temperature dependence of resistivity along the c-axis mark the magnetic phase transitions between paramagnetic and antiferromagnetic (AF) state at TN and the AF 1 -AF2 transition at T I .L arge negative magnetoresistance effects have been observed not only in the AF state as a result of the metamagnetic transition to canted structure ai B,, but also at temperatures far above TN. The latter result is attributed to the existence of AF correlations or short range AF ordering in the paramagnetic range. The value of TN increases with increasing applied pressure, whereas TI simultaneously decreases. It is also found that 13, decreases with increasing pressure. As a consequence, the stability range of the AF- 1 phase expands with applied pressure partially on account of the ground-state AF-2 phase