Functional palatoraphy and modified genioplasty in obstructive sleep apnea

10 patients with obstructive sleep apnea syndrome (OSAS) have been treated with the new surgical procedure functional palatoraphy and modified genioplasty. 5 months after surgery 7 patients with an apnea hypopnea index under 10 were cured. Three therapy refractory patients were all overweight with a body mass index of more than 29 kg/m2. Excessively overweight patients should therefore not be operated. Following the selection criteria we introduced an effective new treatment method for OSAS.     

Bias‐dependent small‐signal monolithic PIN diode modeling

This paper details a new bias‐dependant small‐signal modeling methodology for monolithic PIN diodes. The frequency‐dependent responses of intrinsic p‐i‐n structures are de‐embedded from monolithic microwave integrated circuit PIN diodes of varying size and layout configuration and fit from 6 to 45 GHz to a classical linear model at each of 15 different bias levels. This methodology results in a bias‐dependent intrinsic diode data set that shows excellent agreement with large samples of small‐signal measurements. The models are useful for comparing trade‐offs in electrical performance among PIN diodes of varying size and layout style. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 396–403, 2001.     

Design and analysis of a reconfigurable dual-beam grating antenna for low-cost millimeter-wave beam-steering

This paper presents a reconfigurable dual-beam grating antenna for low-cost millimeter-wave beam steering. Experimental results indicate that this multibeam approach provides over /spl plusmn/50/spl deg/ beam steering at fixed frequencies across the entire 35 to 40 GHz band, with excellent radiation patterns maintained across the scans. An approximate analysis developed for the reconfigurable antenna closely predicts the observed scan angles and main beam radiation patterns across the complete range of scan states. These results should have numerous applications in millimeter-wave beam-steering technology.     

Effect of continuous melatonin infusions on steady-state plasma melatonin levels in rats under near physiological conditions

Over one hundred cases of legionnaires' disease have been linked to ships, and ten cases are known to have died. Most of the cases were associated with cruise ships, but a variety of other vessels were also linked to cases. Few vessels were investigated microbiologically, and the cases associated with ferries were exposed to other sources of infection. Cases appear to be less common among crew members than among passengers. To prevent further cases, ship owners, operators, and captains need to be diligent in maintaining the water and air conditioning systems of their vessels. Whirlpool spas need particular care. Ship-associated cases of non-pneumonic legionellosis appear to be rare.     

Rebound insomnia after hypnotic withdrawal in insomniac outpatients

Interleukin-2 (IL-2) is not only an important immunoregulatory molecule: it is also an important neuroregulatory molecule in the CNS. Investigations in vivo and in vitro have elucidated the following: IL-2 and IL-2 receptors (IL-2R) have been detected in the brain; IL-2 promotes survival and neurite extension of cultured neurons, stimulates oligodendrocyte proliferation and maturation, affects the hypothalamic-pituitary function and produces behavioral and electrocorticogram spectrum changes. Investigations in some laboratories, including ours, have also demonstrated an analgesic effect of IL-2 in the CNS. The molecular structure of the analgesic domain of IL-2 is distinct from the immune domain mediating immunoregulatory effects. A possible mechanism of action of cytokines on the CNS and the immune system or both exists: multiple actions of cytokines could be mediated by distinct domains or functional sites of cytokines interacting with different receptors or receptor subtypes.     

A limitation on the small-scale demonstration of retrodirective microwave power transmission from the solar power satellite

The solar power satellite (SPS) is a future system for transmitting a high-power microwave beam to the Earth using a large, space-based retrodirective array. However, the small-scale demonstration of a prototype retrodirective transmitter for this application faces a basic limitation and associated tradeoffs, which are identified and described in this paper. Computer-simulated examples are presented, and recommendations are made.     

A 10- to 21-GHz, low-cost, multifrequency, and full-duplexphased-array antenna system

This paper presents a novel phased-array antenna system with multifrequency, full-duplex operation, and wide-beam scanning. The system consists of a wideband power divider, a low-loss and low-cost multiline phase shifter controlled by dual piezoelectric transducers (PETS), a four-channel multiplexer, microwave monolithic integrated circuit (MMIC) amplifiers, and a stripline-fed Vivaldi antenna array. The multiline PET phase shifter has a low perturbation loss of less than 2 dB and a total loss of less than 4 dB up to 40 GHz, with a maximum phase shift of 650°. Using dual-aligned PETS for bidirectional phase shifting results in wide scan angles of 38.6°, 37.6°, 43°, and 40° for the four channels at 10, 12, 19, and 21 GHz, respectively. The four-channel diplexer demonstrates low insertion loss with high isolation between channels. The new multifrequency phased-array system provides wide-beam scanning and full-duplex capability using a simple, low-cost architecture. The system can be used for applications in mobile satellite communications     

Out of the Lab and into the Bathroom: Evening Short-Term Exposure to Conventional Light Suppresses Melatonin and Increases Alertness Perception

Life in 24-h society relies on the use of artificial light at night that might disrupt synchronization of the endogenous circadian timing system to the solar day. This could have a negative impact on sleep–wake patterns and psychiatric symptoms. The aim of the study was to investigate the influence of evening light emitted by domestic and work place lamps in a naturalistic setting on melatonin levels and alertness in humans. Healthy subjects (6 male, 3 female, 22–33 years) were exposed to constant dim light (<10 lx) for six evenings from 7:00 p.m. to midnight. On evenings 2 through 6, 1 h before habitual bedtime, they were also exposed to light emitted by 5 different conventional lamps for 30 min. Exposure to yellow light did not alter the increase of melatonin in saliva compared to dim light baseline during (38 ± 27 pg/mL vs. 39 ± 23 pg/mL) and after light exposure (39 ± 22 pg/mL vs. 44 ± 26 pg/mL). In contrast, lighting conditions including blue components reduced melatonin increase significantly both during (office daylight white: 25 ± 16 pg/mL, bathroom daylight white: 24 ± 10 pg/mL, Planon warm white: 26 ± 14 pg/mL, hall daylight white: 22 ± 14 pg/mL) and after light exposure (office daylight white: 25 ± 15 pg/mL, bathroom daylight white: 23 ± 9 pg/mL, Planon warm white: 24 ± 13 pg/mL, hall daylight white: 22 ± 26 pg/mL). Subjective alertness was significantly increased after exposure to three of the lighting conditions which included blue spectral components in their spectra. Evening exposure to conventional lamps in an everyday setting influences melatonin excretion and alertness perception within 30 min.     

Disorders of the circadian sleep-wake rhythm--diagnostic and therapeutic principles

The most important circadian rhythm disorders are presented excluding jet lag syndrome and shift work. Clinical and psychological findings, pathophysiological principles and social consequences are discussed with reference to recent literature. The ICSD classification is reviewed critically and proposals for operationalisation of new diagnostic procedures are offered. The current therapeutic principles are described and it is attempted to develop a more systematic documentation of therapy aiming at the possibility of future outcome-comparison between the presently very heterogenic principles.     

Novel low-cost beam-steering techniques

This paper summarizes and compares several techniques for beam steering without the use of conventional ferrite or solid-state phase shifters. Three methods are presented: a microstrip patch antenna array fed by a dielectric image line (DIL) controlled by a reflector plate, a multimicrostrip line fed Vivaldi antenna array controlled by piezoelectric transducers (PETs) and a movable grating film fed by dielectric image line. Both theoretical analyses and experimental measurements have been carried out. The measurement results agree very well with the predictions. These new techniques have many advantages, including low cost, broad bandwidth, low loss, wide scan angle, and simplicity. These low-cost beam-steering techniques should have many applications in microwave and millimeter-wave commercial systems