Optical parametric chirped pulse amplification and spectral shaping of a continuum generated in a photonic band gap fiber.

A chirped pulse, spectrally broadened in a photonic bandgap optical fiber by 120 fs Ti:Sapphire laser pulses, is parametrically amplified in a BBO crystal pumped by a frequency doubled nanosecond Nd:YAG laser pulse. Without changing the frequency of the Ti:Sapphire, a spectral tunability of the amplified pulses is demonstrated. The possibility to achieve broader spectral range amplification is confirmed for a non-collinear pump-signal interaction geometry. For optimal non-collinear interaction geometry, the pulse duration of the original and amplified pulse are similar. Finally, we demonstrate that the combination of two BBO crystals makes it possible to spectrally shape the amplified pulses.

[Marfan's syndrome and pregnancy. A case report and review of the literature]. / Syndrome de Marfan et grossesse. A propos d'un cas et revue de la littérature.

Marfan's syndrome is a collagen tissue disease, identified at the end of the nineteenth century. The gene for this autosomal dominant disease lies on chromosome 15 and leads to a biochemical disorder yet to be described. We report a case of Marfan's disease in a gravid patient and discuss the complications which may occur. The main risk involves the cardiovascular manifestations of the disease with possible dissection or rupture of the aorta. Preventive surgery, with extra-corporal circulation is required when the diameter of the aorta is greater than 6 cm. Spontaneous abortions and risk of premature birth have also been reported. Delivery itself is not a major risk but should be planned in a setting allowing immediate transfer to a cardiac surgery unit. Pregnancy should be discouraged in patients with Marfan's syndrome if the aortic diameter is greater than 4 cm. When pregnancy occurs, echocardiographic examinations of the mother should be performed monthly for the first 6 months, then bimonthly. Prenatal diagnosis is of little interest, except to detect foetuses at risk at delivery.

[Laparoscopy under local anaesthesia and hypnoanaesthesia about 35 cholecystectomies and 15 inguinal hernia repair]. / Coeliochirurgie sous anesthésie locale et hypnosédation, à propos de 35 cholécystectomies et 15 cures de hernies.

OBJECTIVE: To present hypnosedation and the feasibility of this technique performed for laparoscopic procedure. STUDY DESIGN: Retrospective and descriptive study of feasibility. PATIENTS AND METHODS: Hypnosis can significantly reduce intraoperative requirements of intravenous sedation for surgery under local anaesthesia. Modifications of surgical procedure: laparoscopic surgery under local anaesthesia and hypnosis is performed using a subcutaneous lifting of anterior abdominal wall. Insufflation is only use to push out smoke. If patient or surgical uncomfort happens, moral contract with patient includes convert to general anaesthesia. RESULTS: We performed 35 cholecystectomies; 13 needed convert to general anaesthesia, mainly for peritoneal pain induced by CO(2) insufflation; 22 procedures were completed with patients' satisfaction. Upon 15-hernia repairs, only one patient needed convert to general anaesthesia, for dissection difficulty. CONCLUSION: Probably hypnosis can't be extent to intraperitoneal laparoscopic procedures. On the other hand interest of hypnosis performed for extraperitoneal laparoscopic hernia repair must be explore.

Temporal characterization of short pulses stretched by fiber Bragg gratings.

Short femtosecond pulses at 1054 nm are stretched up to 400 ps by long broadband chirped-fiber Bragg gratings. The temporal profile of the reflected pulses is measured with a cross-correlation scheme. The advantage of this technique over the usual spectral measurements is its high sensitivity, since the temporal profile of reflected pulses is revealed to be strongly affected by the presence of defects in the grating. We show that this method is a good test of the quality of fiber Bragg gratings.