RESUMO
We report on the first results of diode pumped laser operation of Pr3+:LaF3 in a quasi continuous wave (qcw) mode with average output powers of up to 80.0 mW (≈ 161.3 mW qcw) and a maximum slope efficiency of 37% at 719.8 nm. Furthermore it was possible to operate the laser at 537.1 nm and 635.4 nm and to tune the emission wavelength from 609 nm to 623 nm. The pump source was an InGaN laser diode with a maximum output power of 1 W at a central emission wavelength of 442 nm.
Assuntos
Lasers de Estado Sólido , Análise Espectral/instrumentação , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
Single crystals of Dy(3+)-doped YPO(4) have been grown from Pb(2)P(2)O(7) flux and investigated by optical spectroscopy techniques. The energy level scheme of the active ion has been deduced from the low temperature spectra and reproduced by means of a crystal-field calculation. The room temperature absorption spectra have been analysed in the framework of the Judd-Ofelt approach, and the results of this analysis have been applied in a discussion concerning the spectral composition of the visible luminescence.
Assuntos
Doenças Cardiovasculares/etiologia , Obesidade Mórbida/complicações , Adulto , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/cirurgia , Contraindicações , Humanos , Derivação Jejunoileal , Masculino , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/cirurgia , Cuidados Pós-OperatóriosRESUMO
To assess the hemodynamic effects of Clonidine in hypertensive patients (pts) with an acute myocardial infarction (AMI), we administered the drug to 12 such patients either in a single bolus (75--150 micrograms in 5 min - 8 pts) or by continuous infusion (0.4--5 micrograms/min - 4 pts). Hemodynamic measurements were obtained by means of a Swan-Ganz thermodilution catheter, before and 60 min after the administration of the drug. Clonidine did not significantly affected Heart Rate (from 80.5 +/- 3.9 to 78.4 +/- 5.9 beats/min), Mean Pulmonary Arterial Pressure (from 18.6 +/- 1.7 to 15.1 +/- 1 mmHg), Mean Pulmonary Wedge Pressure (from 12.5 +/- 1.1 to 10.6 +/- 0.7 mmHg), central Venous Pressure (from 4 +/- 0.8 to 3 +/- 0.9 mmHg), Cardiac Index (from 2.6 +/- 0.07 to 2.6 +/- 0.7 L/min/m2), Stroke Volume (from 65.2 +/- 2.8 to 68.5 +/- 5.5 ml/b). Conversely Mean Arterial Pressure fell significantly from 127 +/- 3.1 to 96.2 +/- 7.2 mmHg (P less than 0.001). Left Ventricular Systolic Work Index was reduced from 62.3 +/- 3.3 to 50.4 +/- 4.4 gm/beats/m2 (P less than 0.025), Total Systemic Resistances from 1888 +/- 50 to 1412 +/- 117 dyne sec cm-5 (P less than 0.005) and Tension Time Index from 3536 +/- 495 to 2389 +/- 385 x 10(3) mmHg x sec/min (p less than 0.05). Clonidine is a safe and useful drug to obtain a fall of high blood pressure often complicating AMI, without depressing left ventricular performance, as suggested by no significant changes of CI, WP and LVSWI. The reduction of TTI suggests a beneficial effect on the balance between myocardial oxygen delivery and demand. Clonidine is a hypotensive drug which can be safely used in patients with AMI, without depressing the left ventricular performance.