Large anisotropy of ferroelectric and pyroelectric properties in heteroepitaxial oxide layers.

Epitaxial PbZr0.52Ti0.48O3 (PZT) layers were integrated on Si(001) with single PZT {001} orientation, mosaïcity below 1° and a majority of a-oriented ferroelectric domains (∼65%). Ferroelectric and pyroelectric properties are determined along both the out-of-plane and in-plane directions through parallel-plate capacitor and coplanar interdigital capacitor along the <100>PZT direction. A large anisotropy in these properties is observed. The in-plane remnant polarization (21.5 µC.cm-2) is almost twice larger than that measured along the out-of-plane direction (13.5 µC.cm-2), in agreement with the domain orientation. Oppositely, the in-plane pyroelectric coefficient (-285 µC.m-2.K-1) is much lower than that measured out-of-plane (-480 µC.m-2.K-1). The pyroelectric anisotropy is explicated in term of degree of structural freedom with temperature. In particular, the low in-plane pyroelectric coefficient is explained by a two-dimensional clamping of the layers on the substrate which induces tensile stress (from thermal expansion), competing with the decreasing tetragonality of a-domains (shortening of the polar c-axis lattice parameter). Temperature-dependent XRD measurements have revealed an increased fraction of a-domains with temperature, attesting the occurrence of a partial two-dimensional clamping. These observed properties are of critical importance for integrated pyroelectric devices.

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[Conservative treatment of talar dislocation: a case report]. / Traitement conservateur de l'énucléation du talus. A propos d'un cas.

Dislocation of the talus is a rare and serious injury. The functional prognosis is poor due to osteonecrosis of the talus which develops in the majority of cases. We report a case of anterolateral dislocation-enucleation of the right talus (Cauchoix type II) in a 26-Year-old work accident victim. Dislocation was caused by an indirect mechanism. Emergency reduction was performed by external manipulations without repair of the capsuloligamentary structures. At three Years, the right ankle was pain free and stable. Motion was satisfactory: 10 degrees dorsal flexion, 30 degrees plantar flexion. Standard x-rays and magnetic resonance imaging demonstrated moderate narrowing of the anterior talocrural and posterior subtalar joints.

[A triple association: renal malacoplakia, bilateral vulvar hypertrophy, upper limb algodystrophy]. / Triple association: malacoplakie rénale, hypertrophie vulvaire bilatérale, algodystrophie des membres supérieurs.

The authors report a case of malakoplakia of the left renal parenchyma, an uncommon site for an inflammatory disease first described in the bladder by Michaelis and Guttmann in 1902 and Von Hansmann in 1903. This case was observed in a 24-year-old girl with no urological history, presenting with bilateral vulval hypertrophy and reflex sympathetic dystrophy of the upper limbs, in whom malakoplakia of the left kidney was discovered incidentally. Intravenous urography showed two large kidneys with a stretched appearance of the renal pelvis. Pathological examination of the partial nephrectomy specimen revealed the diagnosis of malakoplakia, an inflammatory diseases of the renal parenchyma. The pathogenesis has been only partially elucidated, but probably involves a disorder of macrophage function.