Broadband operation of InGaAsP-InGaAs GRIN-SC-MQW BH amplifiers with 115 mW output power

Broadband operation of GRIN-SC-MQW BH amplifiers is reported with 115 mW output power at 1.54 mu m and 3 dB gain compression. Gain is flat to 0.7 dB over the range 1.42-1.55 mu m. Polarisation sensitivity reduces from 4.5 dB at 1.55 mu m to 1.4 dB at 1.415 mu m.<>     

Ventilatory dynamics during transient arousal from NREM sleep: implications for respiratory control stability

The polysomnographic and ventilatory patterns of nine normal adults were measured during non-rapid-eye-movement (NREM) stage 2 sleep before and after repeated administrations of a tone (40-72 dB) lasting 5 s. The ventilatory response to arousal (VRA) was determined in data sections showing electrocortical arousal following the start of the tone. Mean inspiratory flow and tidal volume increased significantly above control levels in the first seven breaths after the start of arousal, with peak increases (64.2% > control) occurring on the second breath. Breath-to-breath occlusion pressure 100 ms after the start of inspiration showed significant increases only on the second and third postarousal breaths, whereas upper airway resistance declined immediately and remained below control for > or = 7 consecutive breaths. These results suggest that the first breath and latter portion of the VRA are determined more by upper airway dynamics than by changes in the neural drive to breathe. Computer model simulations comparing different VRA time courses show that sustained periodic apnea is more likely to occur when the fall in the postarousal increase in ventilation is more abrupt.     

Effect of glutamine on methotrexate efficacy and toxicity

OBJECTIVE: To examine the effect of oral glutamine (GLN) on the efficacy and toxicity of methotrexate (MTX). SUMMARY BACKGROUND DATA: The use of high-dose chemotherapy regimens is limited by the severity of their toxicities. Oral GLN has been shown to decrease the gut toxicity seen with MTX treatment while enhancing its tumoricidal effect. METHODS AND RESULTS: Studies were done in laboratory rats and in breast cancer outpatients. Fischer 344 rats were randomized to 48 hours of prefeeding with GLN (1 g/kg/day) or an isonitrogenous amount of glycine. Rats were killed 24 hours after receiving a 20-mg/kg intraperitoneal dose of MTX. In the GLN group, there was a threefold increase in total MTX in the tumor as compared with the control group, and this increase was in both the diglutamated and pentaglutamated MTX. Inversely, there was a significant decrease in the total polyglutamated MTX in the gut in the GLN group. Given the results of this preclinical study, the authors performed a phase I trial. Nine patients diagnosed with inflammatory breast cancer received GLN (0.5 g/kg/day) during MTX neoadjuvant therapy, escalating from doses of 40 mg/m2 to 100 mg/m2 weekly for 3 weeks, followed by a doxorubicin-based regimen. No toxicity of oral GLN was detected. No patient showed any sign of chemotherapy-related toxicity. One patient had a grade I mucositis. Except for one, all patients responded to the chemotherapy regimen. Median survival was 35 months. CONCLUSIONS: These studies suggest that GLN supplementation is safe in its administration to the tumor-bearing host receiving MTX. By preferentially increasing tumor retention of MTX over that of normal host tissue, GLN may serve to increase the therapeutic window of this chemotherapeutic age.     

New approach to the manufacture of low-threshold 1.5 ?m distributed feedback lasers

Low-threshold-current (85 mA), oxide isolated InGaAsP/InP distributed feedback (DFB) lasers operating at a wavelength of ? = 1.5 ?m have been produced for the first time using electron-beam-written DFB corrugations overgrown by MOCVD. The control and flexibility afforded by these techniques considerably ease the complexity of DFB laser manufacture.     

Monolithic 1.5 ?m hybrid DFB/DBR lasers with 5 nm tuning range

A new tunable single-longitudinal-mode laser structure is reported. This monolithic hybrid DFB/DBR laser can be electrically tuned over a 5 nm wavelength range. The tuning mechanism employs the depression in the refractive index with injected carrier density, and the tuning range is linked to the period of an internal diffraction grating.     

A short intertrial interval facilitates acquisition of context-conditioned fear and a short retention interval facilitates its expression.

Rats were shocked in a context on two occasions and then tested for fear reactions as indexed by freezing. Rats spent the interval between conditioning trials and between conditioning and test in their home cages. A short interval between context-conditioning trials or between trials involving a discrete conditioned stimulus (CS) produced better learning than longer intervals. A short retention interval between conditioning and test produced better performance than longer intervals. The effects of the intertrial interval on learning are the opposite of those reported previously and are opposite to those predicted by contemporary learning theories. The effects of the training to test interval on performance are predicted by Wagner's sometimes opponent process (SOP) theory (Wagner, 1981). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive affect: A method of content analysis for verbal samples.

Devised a measure of positive affect using content analysis of verbal samples and found it to have satisfactory interjudge reliability. Normative data from 5 groups (29 17-64 yr old psychiatric patients, 32 established college students, 48 incoming college students, 27 20-60+ yr old women reallocated in a housing development, and 200 new mothers) show an association of positive affect levels with the situations Ss were undergoing. As predicted, positive affect levels were independent of (a) Ss' backgrounds (e.g., sex, education level) and (b) Ss' negative affects as measured by the Gottschalk-Gleser Content Analysis Scales, indicating the necessity for measuring people's positive affect when attempting to understand their experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)