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C Chardonnet

Publications and source records attributed to C Chardonnet.

6 recordsLinked to original sources

Long-distance frequency dissemination with a resolution of 10(-17).

We use a new technique to disseminate microwave reference signals along ordinary optical fiber. The fractional frequency resolution of a link of 86 km in length is 10(-17) for a one day integration time, a resolution higher than the stability of the best microwave or optical clocks. We use the link to compare the microwave reference and a CO2/OsO4 frequency standard that stabilizes a femtosecond laser frequency comb. This demonstrates a resolution of 3 x 10(-14) at 1 s. An upper value of the instability introduced by the femtosecond laser-based synthesizer is estimated as 1 x 10(-14) at 1 s.

Journal Article↗

[Evaluation of changing antibiotic prescription habits in a general hospital center].

OBJECTIVE: Two audits of antibiotic prescriptions were conducted within the framework of the fight against bacterial resistance conducted at the Valence Hospital Center (Drôme, France). The first was made between July 1st and 31st 1998 and the second between December 15th 1999 and January 15th, 2000, both based on the prospective observation scheme. PATIENTS AND METHODS: We studied prescriptions written for antibiotics, recording the compound prescribed, the therapeutic indication, the type of infection and the prescriber. Results of these two audits were compared with the chi-square test. RESULTS: The prescriber was correctly identified (name + signature) on 63.1% of the prescriptions in 1998 and on 92.9% in 1999-2000. The patient was correctly identified (name + first name + age) in 89.9% of the prescriptions in 1998 compared with 95% in 1999-2000. For the compounds prescribed, 30.2% of the prescriptions were complete (name + dose + frequency + duration + administration route) in 1998 compared with 44.5% in 1999-2000. The antibiotic was prescribed for prophylactic purposes in 16.2% of the cases in 1998 and in 8.6% in 1999-2000. Empirical curative antibiotic therapy was prescribed in 44.7% of the cases in 1998 and in 49.3% in 1999-2000. Curative antibiotic therapy was prescribed in 16.2% in 1998 and in 9.3% in 1999-2000 for proven infection and with no mention of proof in 22.9% in 1998 and 32.8% in 2000. DISCUSSION: We observed an improvement in the identification of the prescriber, the patient and the drugs used between the two audits. These results were generally satisfactory and reflect the impact of an information campaign conducted after the first audit. Such audits are part of the ongoing policy designed around the antibiotic booklet and within the framework of the newly instituted antibiotic committees.

Anti-Bacterial Agents↗

Carbon Dioxide Laser Saturation Spectroscopy and the Hyperfine Structure of Monosubstituted Ozone 16O16O17O and 16O17O16O

Carbon dioxide lasers have been used in an offset-lock configuration to obtain saturation spectra of ozone, monosubstituted with O-17, at a linewidth of a few kHz. Rich hyperfine structures result from the O-17 nucleus, spin 5/2. These are used, together with earlier microwave data, to obtain the corresponding hyperfine parameters. The spectra also illustrate the sensitivity of hyperfine structures to subtle vibration-rotation interactions. Copyright 1998 Academic Press.

Journal Article↗