Two-dimensional superconducting phase in LaTiO3/SrTiO3 heterostructures induced by high-mobility carrier doping.

In this Letter, we show that a superconducting two-dimensional electron gas is formed at the LaTiO3/SrTiO3 interface whose transition temperature can be modulated by a back-gate voltage. The gas consists of two types of carriers: a majority of low-mobility carriers always present, and a few high-mobility ones that can be injected by electrostatic doping. The calculation of the electron spatial distribution in the confinement potential shows that the high-mobility electrons responsible for superconductivity set at the edge of the gas whose extension can be tuned by the field effect.

[Pre- and postoperative contribution of Doppler ultrasonography in superficial venous surgery of the popliteal fossa].

Aims Of The Study: Does preoperative Duplex Scan (DS) allow to determine anatomy of the ending of the short saphenous vein (SSV), gastrocnemius vein (GV) and reflux in popliteal vein (PV), SSV and GV. Postoperative DS was performed to detect deep vein thrombosis (DVT) and GV thrombosis.

Material And Methods: From June 94 to November 95 one hundred and eighty lower limbs operated for SSV were included consecutively and prospectively.

[Understanding the poor results after surgery for superficial venous insufficiency].

Effectiveness and value of surgical treatment in varicose veins remains difficult to assess for many reasons. They are discussed in details in front of this general review devoted to poor results after varicose vein surgery. An other pathology is often associated with venous insufficiency and is frequently missed and responsible of poor results.

[Effectiveness of combined repeat surgery and sclerotherapy after failure of surgical treatment of varicose veins].

Unlabelled: From January 1985 to December 1986 one hundred and five patients (145 lower limbs) have been treated by redosurgery followed by sclerotherapy. It is a selected group because redosurgery decision was taken both by surgeon and angiologists on the basis that a significant reflux between the profunda system and the superficial system was present. The aim of this retrospective study was to assess results obtained by this therapeutic association with a follow-up from 5 to 6 years.