Normalized pulsed energy thresholding in a nonlinear optical loop mirror.

We demonstrate for the first time, to the best of our knowledge, that a Sagnac interferometer can threshold the energies of pulses. Pulses below a given threshold T are suppressed, while those above this threshold are normalized. The device contains an in-loop tunable isolator and 10.4 m of a highly doped silica fiber. We derive an analytical model of the nonlinear optical loop mirror's pulse energy transfer function and show that its energy transfer function approximates a step function for very high phase shifts (>π). We reveal some limitations of this approach, showing that a step-function transfer function necessarily results in pulse distortion in fast, nonresonant all-optical devices.

Evaluation of antifungal combinations of nystatin-intralipid against Aspergillus terreus using checkerboard and disk diffusion methods.

OBJECTIVE: The objective of this study was to evaluate the efficacy of combinations of nystatin-intralipid, found previously to be more active than nystatin, with antifungals of different mode of activity, against Aspergillus terreus. METHODS: Antifungal activity of combinations of nystatin-intralipid with voriconazole, caspofungin, terbinafine or 5-fluorocytosine were evaluated by the checkerboard and disk diffusion methods. The results were compared to those obtained with nystatin. RESULTS: The combination of nystatin-intralipid with caspofungin exhibited better antifungal activity than each drug alone and resulted in a synergistic interaction in three out of six tested strains of A. terreus. No such effect was obtained with Nystatin and caspofungin. Nystatin-intralipid or nystatin with voriconazole yielded indifferent interactions. When nystatin-intralipid was combined with terbinafine, a strong antagonism was produced in all six A. terreus strains. This effect was observed both by checkerboard and disk diffusion methods. In contrast no interaction or only slight antagonism was observed in the combination of nystatin with terbinafine. Disk diffusion method revealed similar inhibition zones when disks impregnated with 5-fluorocytosine were placed on plain, nystatin-intralipid or nystatin containing agar plates. CONCLUSIONS: Among four tested combinations, only combination of nytatin-intralipid with caspofungin, a representative of the echinocandin class of antifungals, resulted in synergistic interaction. Antagonism obtained by combining nystatin-intralipid with terbinafine can be explained by existence of hydrophobic interaction between these two compounds interfering with their antifungal action. The fact that nystatin-intralipid and nystatin interact differently with other antifungals, may indicate differences in their mechanisms of activity.

[Squamous erythema annulare centrifugum]. / Erythème annulaire centrifuge squameux.

A case of squamous erythema annulare centrifugum has been observed. It was characterized by striking clinical features and peculiar histological findings, including necrosis of keratinocytes. A search for causative factors was negative. Treatment with tar ointment (Brocq) rapidly resulted in dramatic healing of the lesions; however, the usual features of annular psoriasis were absent in our case.

Hypersensitivity reaction on first-time exposure to cuprophan hollow fiber dialyzer.

Forty-five patients who have been maintained on hemodialysis using a regenerated cellulose hollow fiber artificial kidney (HFAK) were dialyzed on a cuprophan HFAK for the first time. Three black patients (6.6%), one male and two females, ages 43-61, who had been stable on hemodialysis for 30-88 months developed hypersensitivity reactions. The recommended setup procedure was carefully followed. Within seconds in 1 patient and within 10-16 minutes in the remaining two, respiratory distress, urticaria, pruritus, hypertension/hypotension, and facial edema developed. Dialysis was discontinued immediately. They were treated with oxygen, epinephrine, and diphenhydramine. Two patients received IPPB treatments and one received IV methyl-prednisolone. After allowing 10-15 minutes for stabilization, the dialysis was resumed on a non-cuprophan HFAK. Patients were discharged with no sequelae. The cause of the hypersensitivity reaction is unknown. It could be due to substances used in the sterilization procedure, to the membrane itself, or to substances that leach out of the potting compound or membrane. Hypersensitivity reaction during hemodialysis has been reported to be very severe or even fatal. Personnel delivering direct patient care should be aware of the symptoms and react quickly with proper treatment. Patients suspected to have this reaction should be changed to a dialyzer without a cuprophan membrane.

[Scanner placement guide and surgical guide in implantology]. / Guide de repérage scanner et guide chirurgical en implantologie.

The pre-surgical investigation may provide added information by the wearing of a detection cad-can indicating the axes of the future implants at the time of the cad-can examination. This stent is made, using a polymerised director mounting, equipped with radio-opaque detectors in aluminium or zinc oxyphosphate sealing cement. The resulted illustration facilitates the concentration between the surgeon and the prosthetist in the definitive choice of the site of implantation. The plaster model, used for the making of the detection cad-can, is used to transfer this information. In the clinic, the latter is supported by a surgical stent. This guide includes: an indexed stabilising portion on the remaining teeth or portions of edentated crest not involved in the surgery; guiding tubes with a diameter of 2.1 mm, made of infiltrated aluminium according to the INCERAM* procedure. The detection cad-can and surgical stent unit permit a correlation between the preimplant investigation phase and the surgery.