Control of the coherence behavior in a SFG interferometer through the multipump phases command.

In this paper, we report on a novel method to control the coherence behavior in a sum frequency generation interferometer powered by two independent pump lines. At the output of the interferometer, the two incoherent fringe patterns must be superimposed to maximize the contrast. The first step consists in canceling the differential group delay. The second one uses the phase control on one pump to synchronize the fringe patterns. This innovative method is experimentally demonstrated with a setup involving a 1544 nm signal and two pump lines around 1064 nm leading to a converted signal around 630 nm. It can be easily extended to a greater number of pump lines.

First On-Sky Fringes with an Up-Conversion Interferometer Tested on a Telescope Array.

The Astronomical Light Optical Hybrid Analysis project investigates the combined use of a telescope array interferometer and nonlinear optics to propose a new generation of instruments dedicated to high-resolution imaging for infrared astronomy. The nonlinear process of optical frequency conversion transfers the astronomical light to a shorter wavelength domain. Here, we report on the first fringes obtained on the sky with the prototype operated at 1.55 µm in the astronomical H band and implemented on the Center for High Angular Resolution Astronomy telescope array. This seminal result allows us to foresee a future extension to the challenging midinfrared spectral domain.

Plasma concentrations and sedative effects of a dexmedetomidine, midazolam, and butorphanol combination after transnasal administration in healthy rabbits.

Plasma concentrations of dexmedetomidine (D = 0.1 mg/kg), midazolam (M = 2 mg/kg), and butorphanol (B = 0.4 mg/kg) were analyzed by liquid chromatography-mass spectrometry (LC-MS/MS) after their simultaneous (DMB) transnasal (TN) administration to healthy rabbits. Time-dependent changes in sedation and antinociception were evaluated by measuring a sedation score based on rabbit's posture, loss of the righting, palpebral and pedal withdrawal reflexes and by instrumental monitoring of rectal temperature, heart rate, arterial blood pressure, pulse-oximetry, and capnometry. The peak plasma concentration (Cmax ) of each drug was reached within 5 min (Tmax ) from DMB-TN administration along with deep sedation and analgesia. Such effects subsided after 45 min into a moderate sedation and analgesia lasting for additional 15 min. All rabbits awakened spontaneously and uneventfully 90 min after DMB-TN administration. During the anesthetic procedure, arterial blood pressure markedly decreased and respiratory depression ensued requiring oxygen supplementation. The results of this study show that all three molecules of the DMB combination were absorbed through the TN route, inducing deep sedation and analgesia suitable for minor surgical procedures. Such combination should be used with caution in rabbits bearing cardiovascular or respiratory diseases because of its ability to induce hypotension and respiratory depression.

Laboratory demonstration of spatial-coherence analysis of a blackbody through an up-conversion interferometer.

In the field of high resolution imaging in astronomy, we experimentally demonstrate the spatial-coherence analysis of a blackbody using an up-conversion interferometer in the photon counting regime. The infrared radiation of the blackbody is converted to a visible one in both arms of the interferometer thanks to the sum-frequency generation processes achieved in Ti-diffused periodically poled lithium niobate waveguides. The coherence analysis is performed through a dedicated imaging stage which mimics a classical telescope array analyzing an astrophysical source. The validity of these measurements is confirmed by the comparison with spatial-coherence analysis through a reference interferometer working at infrared wavelengths.

[Congenital buried penis in children]. / La verge enfouie congénitale de l'enfant.

PURPOSE: Congenital buried penis in children is an uncommon and poorly known entity. The aims of this study were to report an original technique for correction of buried penis and to evaluate its results. PATIENTS AND METHODS: It is a retrospective study of buried penis operated between November 1998 and May 2009. The acquired concealed penis and hypospadias were excluded from this study. The procedure includes several stages: degloving of the penis through a ventral anchor-like incision; division of the adherent layers surrounding the corpora cavernosa; anchorage of the Buck's fascia to the corporeal albuginea at the base of the penis; and ventral cutaneous coverage. The long-term results were evaluated by the parents and the surgeon according to anatomical, functional and aesthetic criterion. RESULTS: Twenty-five boys were evaluated. The mean age at surgery was 27 months (seven days-120 months). Two children required an additional plasty. Results were satisfactory in 24 cases (96%). One child required a redo procedure for unsatisfactory outcome. Of seven children with redundant skin (28%), three underwent a complementary cutaneous excision. CONCLUSION: Congenital buried penis remains a controversial issue. Our technique was simple and easily reproducible. Voiding difficulties, urinary tract infection or strong parental request were the main indications of this surgery in our experience.

Performance of astronomical beam combiner prototypes fabricated by hybrid sol-gel technology.

Integrated optics coaxial two, three and four telescope beam combiners have been fabricated by hybrid sol-gel technology for astronomical applications. Temporal and spectral analyses of the output interferometric signal have been performed, and their results are in mutual good agreement. The results of the characterization method employed are cross-checked using contrast measurements obtained independently, demonstrating that the chromatic differential dispersion is the main contributer to contrast reduction. The mean visibility of the fabricated devices is always higher than 95 %, obtained using a source with spectral bandwidth of 50 nm. These results show the capability of hybrid sol-gel technology for fast prototyping of complex chip designs used in astronomical applications.

Light scattering by pores in transparent Nd:YAG ceramics for lasers: correlations between microstructure and optical properties.

Nd:YAG ceramics for laser applications were elaborated with various residual porosities by reaction-sintering process. The porosity analysis with CLSM and SEM led to the determination of the pore volume fraction after sintering. This study revealed that the mean pore size of Nd:YAG ceramics was around 0.7 microm while the residual porosity was ranging between 10(-1)% and 10(-4)%. These pore contents affect the transparency and laser efficiency of ceramics. The analytical model based on the Mie light scattering fairly fits the experimental data. This demonstrates that the porosity in Nd:YAG ceramics should be lower than 10(-4)% to reach single-crystal laser efficiency.

Hybrid sol-gel planar optics for astronomy.

Hybrid sol-gel planar optics devices for astronomy are produced for the first time. This material system can operate from the visible (0.5 microm) up to the edge of astronomical J-band (1.4 microm). The design, fabrication and characterization results of a coaxial three beam combiner are given as an example. Fringe contrasts above 94% are obtained with a source with spectral bandwidth of 50 nm. These results demonstrate that hybrid sol-gel technology can produce devices with high quality, opening the possibility of rapid prototyping of new designs and concepts for astronomical applications.

Optical fiber systems are convectively unstable.

We theoretically and experimentally evidence that fiber systems are convective systems since their nonlocal inherent properties, such as the dispersion and Raman effects, break the reflection symmetry. Theoretical analysis and numerical simulations carried out for a fiber ring cavity demonstrate that the third-order dispersion term leads to the appearance of convective and absolute instabilities. Their signature is an asymmetry in the output power spectrum. Using this criterion, experimental evidence of convective instabilities is given in a fiber cavity pumped by a pulsed laser.

Laboratory demonstration of an infrared-to-visible up-conversion interferometer for spatial coherence analysis.

We experimentally demonstrate the possibility of retrieving the spatial coherence of an infrared source by using an up-conversion interferometer. Sum-frequency generation in Ti-diffused periodically poled lithium-niobate waveguides in both arms of the interferometer is used to convert the infrared into the visible domain. The fringe contrast of the interference pattern in the visible domain permits us to resolve the spatial separation of two uncorrelated pointlike infrared sources, which simulate a binary star. The validity of these measurements is confirmed through a simultaneous comparison with a reference interferometer working in the infrared domain.

Interferometric coupling of the Keck telescopes with single-mode fibers.

Here we report successful interferometric coupling of two large telescopes with single-mode fibers. Interference fringes were obtained in the 2- to 2.3-micrometer wavelength range on the star 107 Herculis by using the two Keck 10-meter telescopes, each feeding their common interferometric focus with 300 meters of single-mode fibers. This experiment demonstrates the potential of fibers for future kilometric arrays of telescopes and is the first step toward the 'OHANA (Optical Hawaiian Array for Nanoradian Astronomy) interferometer at the Mauna Kea observatory in Hawaii. It opens the way to sensitive optical imagers with resolutions below 1 milli-arc second. Our experimental setup can be directly extended to large telescopes separated by many hundreds of meters.

[Thyrotoxicosis periodic hypokalemic paralysis]. / Paralysie périodique hypokaliémique et hyperthyroïdie chez un caucasien.

Periodic hypokaliemic paralysis is an usual cause of severe hypokaliemia. Thyrotoxicosis periodic paralysis (TPP) is less common. Incidence is high in Asian people and rarely reported in caucasian people. We describe the case of a young caucasian male, with a TPP. Clinical symptoms of hypokaliemia are strong, when thyrotoxicosis symptoms appear only on blood tests. The clinical course is good with beta-blockers and antithyroid treatment. These treatments induce a total clinical and biological cure. In all the cases of hypokaliemic paralysis, even without symptom, an hyperthyroïdia must be searched for.

Orbital frustration at the origin of the magnetic behavior in LiNiO2.

We report on the ESR, magnetization, and magnetic susceptibility measurements performed over a large temperature range, from 1.5 to 750 K, on high-quality stoichiometric LiNiO2. We find that this compound displays two distinct temperature regions where its magnetic behavior is anomalous. With the help of a statistical model based on the Kugel'-Khomskii Hamiltonian, we show that below T(of) approximately 400 K, an orbitally frustrated state characteristic of the triangular lattice is established. This then gives a solution to the long-standing controversial problem of the magnetic behavior in LiNiO2.

All-guided stellar interferometer with an integrated optics recombiner.

We report laboratory tests of an all-guided stellar interferometer used for optical aperture synthesis. In anticipation of use of the interferometer in space missions, this research is focused especially on compactness of the recombining device. The coherent transport and delay lines are implemented with polarization-maintaining fiber. Beam recombination is achieved by means of an integrated optics component. This two-arm interferometer operates at 670-nm mean wavelength and allows for a 24-cm correction for the differential air path.

Kilometric optical fiber interferometer.

We report on a preliminary experimental study of an interferometer built with two 500 meters long arms made of polarization maintaining optical fibers. The control of the field polarization state along the single-mode fiber arms enables to measure fringe contrast up to 93% with a laser source emitting a 1290nm carrier wavelength. Tests achieved with broadband spectrum exhibit dispersion differential effect resulting from fiber inhomogeneities. Partial compensation of this effect is achieved introducing additional fiber pieces on one arm.

[Hypocomplementemic urticarial vasculitis]. / Vascularite urticarienne hypocomplémentémique.

BACKGROUND: Low-complement urticarial vasculitis is an uncommon condition associating urticaria, glomerulonephritis, obstructive ventilatory disorders, and anti-Ciq antibodies. CASE REPORT: We report a case in a 34-year-old woman who developed urticaria with purpura, membranoproliferative glomerulonephritis (creatinine 238 mumol/l) and bronchial obstruction with bronchectasia. Total complement and the C3 fraction were low. Anti-C1q antibodies were found in the serum and anti-DNA antibodies were negative. Aggravation of the respiratory and renal failure progressed despite corticosteroid therapy, leading to death at 4 months. DISCUSSION: Bronchial obstruction in low-complement urticarial vasculitis results from emphysema and is often life-threatening. Our case exhibited an unusual feature due to the lack of radiodetectable emphysema, the presence of bronchectasia and the rapid degradation of the respiratory function.

Laboratory imaging stellar interferometer with fiber links.

We report on the implementation of an end-to-end imaging demonstrator to validate the concept of optical fiber use in high-resolution aperture synthesis in astronomy. As the coherent transport of light has been conclusively investigated, this study is focused primarily on the accuracy and reliability of the experimental data. In the framework of the European Space Agency project Optical Aperture Synthesis Technologies (OAST), the telescope array's complexity is minimized such that a realistic concept for a future space mission can be proposed. The reconstructed images are obtained by use of a particular self-calibration procedure that was designed to process the visibility contrast and the related weak phase information (one phase closure for each visibility triplet).

[Adverse effects and medication errors: incidence and role of the organization of drug distribution]. / Effets indésirables et erreurs de médication: incidence et rôle de l'organisation du circuit du médicament.

The true incidence of adverse drug events is controversial and there are few data concerning the percentage of potentially preventable adverse drug events. Over 2 months, in two internal medicine units, we asked the staff to report adverse drug events. All incidents were evaluated: adverse drug events (preventable and non-preventable) and potential adverse drug events (non-intercepted potential adverse drug events and intercepted potential adverse drug events). The severity, the stage in the process at which the error occurred and the type of error were evaluated by a physician reviewer. Over the 240 admissions, the incidence of adverse drug events is 18 per 1000 patient-days. The system design caused 77 per cent of the incidents. The medication errors occurred at all stages from ordering to administration. Adverse drug events resulting in medication errors (n = 22) were more serious than non-preventable adverse drug events (n = 26) (p = 0.003). A prevention strategy by pharmacovigilance centres (Centres Régionaux de Pharmacovigilance) should target all stages of the drug delivery process.

Polarization control in a large-stroke optical fiber delay line.

In the context of an optical fiber delay-line implementation by use of silica fiber stretching capability, we experimentally demonstrate that highly birefringent fibers preserve their ability to maintain the polarization coherence in spite of the high magnitude of the stresses applied to them during large stretching. Two experimental demonstrations are presented. In the first, polarization cross coupling versus stretching is characterized. This stretching induces a variation of group delay in the span 0-45 cm. The second is a test of the fiber stretcher in an interferometric application.