Strain-compensated MQW electroabsorption modulator for increasedoptical power handling

InGaAsP MQW electroabsorption modulators with compressive strain in the wells and tensile strain in the barriers provide easier escape of photogenerated holes and operate at higher intensities before suffering saturation. Hole escape from wells is enhanced by a reduced energy difference between heavy-hole states in the well and light-hole states in the barrier     

Double-blind comparison between nifedipine and amlodipine for the treatment of essential hypertension

Nifedipine is an effective compound for the treatment of hypertension. However, even as a tablet formulation it is relatively short acting requiring two or three times daily administration. Amlodipine is a long-acting calcium antagonist and effectively lowers BP in patients with essential hypertension. In the present study we compared the BP-lowering effect of nifedipine and amlodipine in patients with essential hypertension. Thirteen patients were studied. They had been on nifedipine tablets for at least four weeks and DBP had been consistently > 95 mmHg. After a further month run-in on nifedipine they entered a randomised double-blind crossover study of one month' treatment with either nifedipine tablet (20 mg twice daily) or amlodipine (5 mg once daily). BP was measured 12 and 2 hours after the last dose of nifedipine and 24 and 2 hours after the last dose of amlodipine. There was a significant peak/trough effect while on nifedipine tablets, the BP being significantly higher at 12 hours than at 2 hours after the last dose (155.2/90.9 +/- 4.6/1.7 vs. 136.1/84.8 +/- 4.3/1.7 mmHg; P < 0.001/P < 0.005). There was no overall difference in BP between nifedipine and amlodipine treatment when BPs were taken at the respective troughs (i.e. 12 hours and 24 hours). If anything, amlodipine tended to be slightly more effective at least on supine SBP (155.2/90.9 +/- 4.6/1.7 vs. 147.6/89.1 +2- 4.3/1.8 mmHg; P < 0.05, NS). In conclusion, amlodipine given once daily is at least as effective as nifedipine tablets given twice daily in patients with essential hypertension.     

Linear adaptive control of a single-tether system

A control law for a single-tether orbiting satellite system based on a reduced order linear adaptive control technique is presented. The main advantages of this technique are its design simplicity and the facts that specific system parameters and model linearization are not required when disigning the conroller. Two controllers are developed: one which uses only tension in the tether as control actuation and one which uses both tension and in-plane thrusters as control actaution. Both a sixth-order non-linear and an 11th-order bead model of a tethered satellite system are used for simulation purposes, demonstrating the ability of the controller to manage an uncertain system. Retrieval and stationkeeping results using these non-linear models and the linear adaptive controller demonstrate the feasibility of the method. The robustness of the controller with respect to parameter uncertainties is also demonstrated by changing the non-linear model and parameters whithin the model without redesigning the controller.     

Long-term follow-up of Perthes' disease treated nonoperatively

Forty-six patients with Perthes disease treated nonoperatively were reviewed 10 to 43 years later. The median follow-up was 17 years. The patients were analyzed according to sex, age of onset, quantity of head involvement, type of treatment, duration of treatment, functional end result based on the Harris hip scale, and anatomic end result based on Mose templete evaluation. Most patients were treated with an ischial weight-bearing brace. The anatomic results of this treatment tended to be poor, probably worse than no treatment at all. In general, poor results were correlated with late onset, greater quantity of head involvement, and lateral subluxation of the femoral head. As reported in other series, the anatomic results did not correlate well with the functional results, only two patients having Harris hip scales below 70.     

Some problems in faculty selection of patients for supervised psychoanalysis

The selection of patients for supervised analysis by candidates involves special tasks in evaluation and prediction. A number of problems emerge when the entire faculty of an institute participates in evaluating such patients. These include the different ways in which the initial consultant and the Admitting Psychoanalyst view their roles; insufficient consideration given to the specific criteria of suitability for analysis by a candidate; and the tendency to emphasize oedipal pathology while overlooking relevant ego capacities.