RESUMEN
The Phase Doppler Anemometer (PDA) technique measures particle diameter assuming sphericity. A means for detecting nonsphericity has usually been implemented in commercial PDA systems to avoid sizing errors if the sphericity assumption is not valid. In the present research the response of standard and planar PDA systems is examined experimentally in more detail by passing nonspherical droplets of known shape through the measurement volume. The effectiveness of nonsphericity detection schemes can be evaluated, and furthermore the influence of the droplet oscillations on the frequency and phase evolution of individual signals can be quantified. The light scattering from such particles has been simulated by using geometric optics, and the computed response of standard and planar PDA systems agrees well with the experimental observations. We conclude with some remarks concerning the possibilities of characterizing the nonsphericity with PDA systems.
RESUMEN
Light scattering from cylindrical particles has been described with geometric optics. The feasibility of determining the particle diameter with a planar phase Doppler anemometer has been examined by simulations and experiments. In particular, the influence of particle orientation on measurability and measurement accuracy has been investigated. Some recommendations for realizing a practical-measurement instrument have been presented.
RESUMEN
Pain after extraction of two antagonistic third molars was chosen to compare the analgesic effects of single doses of naproxen-sodium (825 mg) and paracetamol (1 000 mg). 124 patients of both sexes, aged from 14 to 41 years, took part in the trial which was of the double blind double dummy type with randomization into one or the other treatment. In all, 89 patients were acceptable for inclusion and followed the protocol correctly. The two treatment groups were statistically matched with regard to age, diagnosis, time of surgery and post-operative drug taking. The results were assessed by the patients on individual report-cards and by the clinician on the control visit. The analgesic effect began at the same time with naproxen-sodium and paracetamol but lasted longer (over 12 hours) with naproxen-sodium. During the 12-hour observation period, 43% of patients on naproxen-sodium refrained from taking an escape drug, as against 23% of patients on paracetamol, the difference being significant (alpha = 5%). Complete pain relief was obtained in 41% of patients under naproxen-sodium and in only 18% of patients under paracetamol. Two side-effects were noted in the paracetamol group and none in the naproxen-sodium group. In this particular pain model, the analgesic activity of naproxen-sodium proved statistically stronger and more durable than that of paracetamol.
Asunto(s)
Acetaminofén/uso terapéutico , Naproxeno/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Distribución AleatoriaRESUMEN
The use of a 1% fluore gel, for ten minutes every day during the irradiation period and after that twice a week, constitutes an excellent protection for the good teeth located in the Tele-Coblat irradiation area. This will avoid the systematic ablation of the good teeth.
Asunto(s)
Caries Dental/prevención & control , Neoplasias Faciales/radioterapia , Flúor/uso terapéutico , Neoplasias de Cabeza y Cuello/radioterapia , Traumatismos por Radiación/prevención & control , Caries Dental/etiología , Geles , Humanos , Enfermedades Mandibulares/prevención & control , Osteorradionecrosis/prevención & control , Extracción DentalAsunto(s)
Diente Molar/cirugía , Germen Dentario/cirugía , Diente Impactado/cirugía , Niño , Humanos , Mandíbula/cirugíaRESUMEN
After a brief account of the history and pathogeny, two cases are described of sub-angiomal bone hypo and hypertrophy. Other cases in the literature are recalled. Finally, a differential diagnosis is given.