High-efficiency Ge thermo-optic phase shifter on Ge-on-insulator platform.

We report on a Ge thermo-optic (TO) phase shifter on a Ge-on-insulator (GeOI) platform for mid-infrared (MIR) integrated photonics. Numerical analysis showed that the Ge TO phase shifter can realize three times higher modulation efficiency than a Si TO phase shifter, owing to the large TO coefficient and refractive index of Ge. The Ge TO phase shifter, operating at a wavelength of 1.

Comparative effects of etomidate, ketamine, propofol, and fentanyl on myocardial contractility in dogs.

Purpose: The present study was carried out to determine the direct effects of etomidate, ketamine, propofol, and fentanyl on myocardial contractility, and whether fentanyl would enhance the myocardial depression caused by propofol.

Method: The anesthetics were injected directly into the circuit that supplied blood to the left circumflex coronary artery (LCX) in anesthetized open-chest dogs. Myocardial contractility was evaluated from measurements of percent segmental shortening (%SS).

Effect of ONO-1101, a novel short-acting β-blocker on hemodynamic responses to isoflurane inhalation and tracheal intubation.

Purpose: We investigated the effect of a new ultrashort-acting β-blocker, ONO-1101, on hemodynamic responses to isoflurane inhalation and tracheal intubation.

Methods: Fifty-four ASA PS 1 or 2 patients were randomly allocated to receive either ONO-1101, 0.04 mg·kg·min, or saline prior to tracheal intubation.

Effects of sevoflurane with and without nitrous oxide on human cerebral circulation. Transcranial Doppler study.

Background: This study was designed to evaluate the effects of sevoflurane with and without nitrous oxide on human middle cerebral artery (MCA) flow velocity, cerebrovascular carbon dioxide reactivity, and autoregulation compared with the awake state using transcranial Doppler ultrasonography.

Methods: In 14 patients, the time-mean middle cerebral artery flow velocity (Vmca) was measured when the end-tidal carbon dioxide level was approximately 30, 40, and 50 mmHg under the following conditions: (1) awake; (2) with 2% (1.2 MAC) sevoflurane; and (3) with 1.

Phosphatidylinositol responses are involved in the vascular effects of thiamylal and fentanyl.

Although thiobarbiturates potentiate, and fentanyl attenuates peripheral vasoconstriction, the intracellular mechanism involved in this phenomenon is not clear. Because smooth muscle contraction induced by alpha 1-adrenoceptor agonists is mediated by the phosphatidylinositol (PI) response, this study was carried out to clarify if thiamylal and fentanyl affect the norepinephrine-induced PI response in rat aortic slices. Rat aortic slices were incubated in Krebs-Henseleit solution containing 5 mM LiCl, [3H]myo-inositol, and varying concentrations of thiamylal or fentanyl.