J Llinares | PubMed Health

PubMed2005

Comment on "Theory of tailoring sonic devices: diffraction dominates over refraction".

Recently, Garcia et al. [Phys. Rev. E 67, 046606 (2003)] studied theoretically several acoustic devices with dimensions on the order of several wavelengths. Those authors also discussed experimental results previously reported by several of us [Phys. Rev. Lett. 88, 023902 (2002)]] and concluded that it is diffraction rather than refraction that is the dominating mechanism explaining the focusing effects observed in those experiments. In this Comment we reexamined their calculations and discussed why some of their interpretations of our results are misleading.

Comment↗

PubMed2003

Impact of analgesic drug-use guidelines for the management of postoperative pain: a drug utilization study.

OBJECTIVE: Postoperative pain is inadequately treated in many surgical settings. The present study evaluates the impact of analgesic drug-use guidelines in the management of postoperative pain. PATIENTS AND METHODS: A prospective drug utilization study was carried out in 3 stages in a traumatology, orthopedic and rehabilitation tertiary hospital. The first stage, aimed at describing the patterns of use of analgesic strategies in the management of postoperative pain, identified habits, practices and misconceptions regarding this therapeutic area. After this, an ad hoc representative institutional working group agreed on analgesic drug-use guidelines for the management of postoperative pain. These were then published, presented and discussed with surgeons and nurses. After the guidelines had been implemented, their impact was evaluated in terms of the analgesics used, their dosage and their administration schedule. RESULTS: 101 patients were studied before the implementation of the guidelines and 108 patients after. Patients receiving opiate analgesics during the immediate postoperative period increased from 70-94% (p < 0.05). First-choice analgesics used according to the guidelines increased from 40-89% of choices after the implementation of the guidelines (p < 0.05). Administration of analgesics at regular predetermined intervals increased from 45-58% of medical orders, but this increase was not statistically significant (p = 0.07). Prescription of analgesics at adequate doses increased from 67-87% (p < 0.05). CONCLUSION: Education on the treatment of postoperative pain is made up of several messages including the drug of choice and dose regimen. Prescribers seemed more receptive to a change in drug rather than issues related to the correct dose regimen. More research is needed to assess how educational activities can improve the management of postoperative pain.

Adult↗

PubMed1999

Large two-dimensional sonic band gaps.

We show that absolute sonic band gaps produced by two-dimensional square and triangular lattices of rigid cylinders in air can be increased by reducing the structure symmetry. In the case of square lattices, symmetry reduction is achieved by a smaller diameter cylinder placed at the center of each unit cell. For triangular lattices the reduction is achieved by decreasing the diameter of the cylinder at the center of the hexagons in the lattice. Theoretical predictions are also demonstrated experimentally: starting from a honeycomb lattice (using cylinders of 4 cm of diameter size and 6.35 cm nearest-neighbor distance) we have studied the transition to a triangular symmetry by putting rods with increasing diameter (in the range 0.6-4 cm) at the center. The greatest enhancement of the attenuation strength observed in transmission experiments has been obtained in the high frequency region for diameter ratios in the range 0.1-0.3.

Journal Article↗