Search

We report on the electronic transport properties of epitaxial La1/3Sr2/3FeO3 films using temperature dependent resistivity, Hall effect, and magnetoresistance measurements. We show that the electronic phase transition, which occurs near 190K, results in a change in conduction mechanism from nonadiabatic polaron transport at high temperatures to resistivity behavior following a power law temperature dependence at low temperatures. The phase transition is also accompanied by an abrupt increase in apparent mobility and Hall coefficient below the critical temperature (T*). We argue that the exotic low temperature transport properties are a consequence of the unusually long-range periodicity of the antiferromagnetic ordering, which also couples to the electronic transport in the form of a negative magnetoresistance below T* and a sign reversal of the Hall coefficient at T*. By comparing films of differing thicknesses, stoichiometry, and strain states, we demonstrate that the observed conduction behavior is a robust feature of La1/3Sr2/3FeO3. [ABSTRACT FROM AUTHOR]

The electronic phase diagram of epitaxial La1-xSrxFeO3 films is presented. The films were grown on SrTiO3 using molecular beam epitaxy with post-growth annealing to minimize oxygen vacancies. Insulating behavior is observed from x = 0-0.9, with metallic conduction only present for x = 1.0. While the La-rich compounds exhibit polaron conduction over all temperatures measured, the Sr-rich films exhibit an electronic phase transition within the compositional window of x = 0.49-0.9 as revealed by temperature-dependent resistivity measurements. The transition temperatures are found to decrease with increasing Sr content. The constructed phase diagram is discussed in the context of other 3d eg perovskite systems including manganites and cobaltites. [ABSTRACT FROM AUTHOR]

Plasma MHPG levels and AMDP rating score were measured in depressed patients before treatment. and a follow-up study was performed during the next 3 months of drug therapy to detect possible relationships between the parameters. Before treatment, MHPG level were moderately lower in depressed than in age- and sex-matched normal subjects. Bipolar depressed patients presented the lowest values. In the three diagnostic groups (DSM-III), antidepressant treatment resulted in a significant decrease of mean Levels in unipolar and dysthymic depressed. but not in bipolar depressed patients. When the type of antidepressant was considered, imipramine (IMI)- or desipramine (DMI)-treated patients, but not fluvoxamine (FLU)-treated, also decreased their mean values of MHPG. with minor difference between improved and non-improved patients. However, when patients were grouped according to their pattern groups (low (LL) high (HL), or normal (NL) baseline MHPG levels), interesting information emerged; improvement of clinical state of patient (i.e. 60 per cent of AMDP baseline reduction) resulted in 'normalization' of erratic values (HL and NL) whatever the treatment, while in non-improved patients such evolution was not observed. In the latter group, change in MHPG levels was only drug-related (decrease in IMI-DMI-treated and no change in FLU-treated values). Results suggest that mechanisms of buffering NA activity were lost in endogenous depression and restored in patients responding to treatment. [ABSTRACT FROM AUTHOR]

Two unselected groups of patients, affected by a mono-hemispheric cerebral lesion, were studied in two seperate services by means of various tasks of copying drawings, in order to check the hypothesis of a qualitative difference between unilateral spatial neglect (USN) of right and left brain-damaged patients. In both experimental groups drawing asymmetries were found to be of slight importance among the left hemispheric patients, consisting chiefly in a tendency to omit some figures lying on the right half of the models, and to be definitely more severe in the right braindamaged patients, where the main pattern of USN seemed to be the tendency to leave unfinished the left half of the drawings. A second aim of the study was to describe some less frequent features of USN, sometimes found in patients who were recovering from a severe damage of the minor hemisphere. These patterns of USN seemed to suggest that the core of unilateral spatial neglect consists in a peculiar disorganization of the type of synthesis of the sensory data which seems characteristic of the minor hemisphere. [ABSTRACT FROM AUTHOR]

A 66-year-old white man developed hypothyroidism after 5 years of lithium therapy. The condition persisted after switching to carbamazepine. Thyroid hormone substitution improved the response to psychotropic drugs and has helped to maintain stable mood. [ABSTRACT FROM AUTHOR]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]