Spatially dispersive amplification in a 12-core fiber and femtosecond pulse synthesis by coherent spectral combining.

A compact scheme is demonstrated for amplification and synthesis of ultrashort pulses by fiber amplifiers. Femtosecond pulses are split in 12 different spectral bands which are amplified separately in the 12 cores of a multicore ytterbium doped fiber. Combining the amplifier outputs together with the intensity and phase management of the spectral bands lead to short pulse synthesis with adjustable pulse shape. The scheme gave an x 92 enhancement in amplified power before the onset of nonlinear effects by comparison with standard stretcher free amplification in a single core fiber.

Linear and nonlinear optical properties of gold nanoparticle-doped photonic crystal fiber.

We report on the production of air/silica photonic crystal fiber doped with gold nanoparticles. The stack-and-draw technique was used to combine a gold nanoparticles-doped silica core rod synthesized by the sol-gel route with capillaries drawn from commercially available silica tubes. The presence of nanoparticles in the core region was confirmed at the different steps of the process down to the fiber geometry, even after multiple drawings at ~2000 °C. Optical properties of the fiber were investigated and put in evidence the impact of gold nanoparticles on both linear and nonlinear transmission.

Optical properties of Bismuth-doped silica core photonic crystal fiber.

Optical properties of a Bismuth-doped pure silica sol-gel core photonic crystal fiber (PCF) were investigated. We report on the absorption, CW luminescence and time resolved luminescence spectra at different excitation wavelengths at room temperature. Complex structure of the energy levels of Bismuth-connected centers in pure silica glass is put in evidence.

White-light cw-pumped supercontinuum generation in highly GeO(2)-doped-core photonic crystal fibers.

GeO(2)-doped-core photonic crystal fibers show greatly enhanced Kerr and Raman responses with respect to pure silica without any significant modification of the group-velocity dispersion curve. We show that such fibers allow a significant improvement of cw-pumped supercontinuum generation. We report for the first time to our knowledge the generation of a white-light cw-pumped supercontinuum spanning from 470 nm to more than 1750 nm.

[Radial approach in the elderly]. / Abord radial chez le sujet âgé.

Due to the steady increase in life expectancy, the number of patients over 80 years of age proposed for coronary angioplasty is increasing significantly. The elderly patient is a patient at high cardiovascular risk and high risk of bleeding; whose severity of prognosis depends of comorbidities. The radial approach presents particularities and technical difficulties that have to be known in this part of the population, but reduce vascular and hemorrhagic complications, as well as mortality. Because of greater safety, the radial approach is therefore the first choice for the elderly.

[Management of high-risk pulmonary embolism with pulmonary artery trunk mobile thrombus]. / Gestion d'une embolie pulmonaire à haut risque avec thrombus mobile du tronc artériel pulmonaire.

The presence of a right intraventricular thrombus is a marker of severity of pulmonary embolism (PE), and is associated with high mortality. We report the case of a young patient with a PE postoperative of patellar tendon surgery. The cardiac echocardiography at its admission revealed a voluminous mobile thrombus of 1.7cm diameter located on the pulmonary trunk. Systemic thrombolysis was performed because of respiratory deterioration allowing a rapid disappearance of the thrombus and recovery. Our case emphasizes the value of a complete ultrasound analysis centered on the pulmonary trunk in the case of intermediate-risk PE. No recommendation exists on the management of these right ventricular thrombi, thrombolysis appearing to be the first-line treatment.

[Contribution of intracoronary imaging in acute coronary syndrome]. / Apport de l'imagerie endocoronaire dans le syndrome coronarien aigu.

Acute coronary syndrome (ACS) remains a major cause of mortality and morbidity in the world, although it has considerably decreased through technical and pharmacological advances. The physiopathological approach of the ACS has progressed considerably in recent years thanks to the anatomopathological work and the data of the endocoronary imaging, in particular of the endovascular ultrasound (IVUS). Plaque rupture is the most common cause of ACS, however OCT (optical coherence tomography) studies have shown that surface plaque erosion was more common than thought. The use of OCT in the ACS may prove to be a valuable diagnostic aid: study of the culpable lesion, spontaneous coronary dissection or intramural spontaneous hematoma, stent thrombosis; from a therapeutic point of view: reduction of the risk of stent malapposition, additional technique, delayed stenting, implantation of a bioresorbable stent, medical treatment of ACS without stenting. Endocoronary imaging, especially OCT, will of course never be systematic as treatment of ACS, but providing excellent value for both diagnosis and treatment, it must be an integral part of the therapeutic arsenal available in cathlab.

[Radial approach in women]. / La voie d'abord radiale chez la femme.

Since the first series of coronary angiographies through the radial approach reported by Campeau in 1989, the radial route has become a major approach, used in up to 95 % of PCIs in some centers. As documented by this clinical case, and although registries show that the radial approach is underused in women compared to men, women benefit from the radial approach mainly by reducing the bleeding risk. Indeed, despite more frequent difficulties encountered by using this approach in women, the radial approach has to be preferred because it reduces haemorrhagic complications and death in comparison to the femoral route.

[Purulent pericarditis in a patient with diabetes mellitus treated by percutaneous pericardiocentesis]. / Péricardite purulente chez un patient diabétique traitée par drainage péricardique percutané.

Purulent pericarditis seldom occurs in Western countries, yet its mortality rate remains high between 20 and 35 % despite early treatment. We report the case of a 43-year-old patient admitted in the intensive cardiologic care unit with a pre-tamponade, requiring an immediate percutaneous pericardiocentesis allowing the drainage of a purulent effusion. Evolution with antibiotic therapy adapted according to the bacteriological findings was favorable and 3-months follow-up shows a near complete regression of the effusion. This case recalls us this rare diagnosis entity and illustrates the possibility of a mere percutaneous pericardial drainage with the condition of a strict medical surveillance.

Improvement of hemorheological abnormalities in alcoholics by an oral antioxidant.

BACKGROUND/AIMS: It has been shown that alcohol impairs erythrocyte (red blood cell) membrane fluidity and lipid composition. The aim of this study was to test the effect of a novel acid-resistant antioxidant on the hemorrheology in alcoholics. METHODOLOGY: Thirty alcoholics (25 males, 5 females; mean age: 42 years; range: 31-54; 150 g ethanol/day for 3-5 years) were enrolled into the study. Patients were randomly and double-blindly allocated into 2 groups which were given, for a 2 week period, 18 g/day of Bionormalizer (obtained from biofermentation of carica papaya, pennisetum purpureum, sechium edule, Osato Res. Foundation, Gifu, Japan) dissolved in 5 mL of water at bedtime and 3 hours prior to examination. Placebo consisted of flavored sugar. Healthy teetotalers served as control. On the examination day, blood samples were taken for testing: routine tests, plasma glutathione, ascorbic acid, selenium, plasma lipid hydroperoxides and alpha-tocopherol. Erythrocytes were separated and tested for red blood cell malonyldialdehyde and glutathione content. The hemorheological studies were as follows: blood and plasma viscosity, whole blood filterability, red blood cell membrane fluidity by electron spin resonance, red blood cell aggregation index by photometric rheoscopy and red blood cell deformability by ektacytometry. RESULTS: As compared to healthy controls, alcoholics on placebo treatment showed no change of plasma viscosity but a significantly higher red blood cell malonyldialdehyde, blood viscosity (P < 0.05) and lower plasma glutathione, whole blood filterability and red blood cell fluidity (P < 0.01). No relationship appeared between biochemical tests and red blood cell membrane fluidity. Bionormalizer group showed a significant recovery to control values of either blood viscosity and whole blood filterability (P < 0.01) and a partial, although significant, improvement of red blood cell membrane fluidity, red blood cell malonyldialdehyde and plasma glutathione (P < 0.05). As compared to healthy control, red blood cell aggregation decreased in alcoholics (P < 0.05) and was not affected by Bionormalizer. However, Bionormalizer significantly improved the reduced red blood cell deformability (P < 0.05 vs. alcoholics) and this parameter correlated with red blood cell malonyldialdehyde (r: 0.62. P < 0.05). CONCLUSIONS: These preliminary data suggest that an effective antioxidant supplementation is able to improve the hemorrheology in alcoholics either by directly affecting the ethanol-related lipoperoxidation and xanthine oxidase system activation and/or by modifying red blood cell membrane characteristics.

[Health education and AIDS. A randomized controlled trial]. / Education pour la Santé et SIDA. Un essai comparatif avec tirage au sort.

In 1987 a small health education research team in Montpellier became interested in AIDS prevention among high school students (15-19 years old). Studies at that time indicated that the majority of the youth were relatively well informed about AIDS, for example 99% of those questioned knew that the disease was transmitted by sexual intercourse or by the exchange of contaminated needles. Further studies indicated, however, that the young people did not feel that the subject concerned them personally--it was considered a problem like many others. The team decided therefore to design a programme which would involve the young people, and thus motivate them not only to question, but to look for answers and implicate themselves in the search for information. The programme design consisted in creating video workshops in selected high schools. Adults with different backgrounds were trained in video production and communication skills in order to develop sufficient staff for workshop supervision. A network of available specialists was recruited for consulting purposes and a specialized library which included audiovisual materials was created so that the young people would have sufficient resources available for their research. In order to incite the students to contemplate the subject of AIDS and all that it involves, a contest was held. The theme was simply, "AIDS" and the duration was the length of the 1988-89 school year. Eight workshops were created in eight different schools. The teams were created quite spontaneously and the dynamic of interrogation anticipated was realized. With the help of trained adult supervisors, each team started their project by designing a five minute video.(ABSTRACT TRUNCATED AT 250 WORDS)