Duplication of 16q and deletion of 15q.

A patient with distal arthrogryposis, congenital dislocations of the hips, a prominent forehead, epicanthal folds, thin lips, and a poorly defined philtrum was found to have a deletion of 15q and a duplication of 16q. Her mother, maternal grandmother, and great grandmother had a balanced t(15q-, 16q+). The gene for adenine phosphoribosyl transferase was assignable to the 16q22----16qter area that was duplicated.

Dopaminergic antagonists: effects of 1,2,3,4-tetrahydroisoquinoline and its N-methyl and N-propyl homologs on apomorphine- and L-dopa-induced behavioral effects in rodents.

N-Methyl-1,2,3,4-tetrahydroisoquinoline (MTIQ) antagonized apomorphine (APO)-induced stereotypy in a dose-related manner when injected i.p. in rats and attenuated L-dopa-induced hyperactivity in mice. 1,2,3,4-Tetrahydroisoquinoline (TIQ) and its homolog, N-n-propyl-, also blocked APO-induced stereotypy when given similarly. No significant difference was found between the amounts of radioactivity in the brain homogenates of MTIQ- and saline-pretreated rats after injection with [3H] APO. This suggested that MTIQ did not antagonize the behavioral effects of APO by blocking its entry into the brain. Mice fed ad libitum for 90 days with Purina Chow mixed with TIQ (5.0 mg/g) displayed behavioral supersensitivity in comparison with controls when injected with L-dopa (0.40 g/kg i.p.) after pretreatment with carbidopa. This was parallelled by a significant increase of dopamine-related adenylate cyclase activity measured in homogenates of caudate nuclei. The similarity between the behavioral effects induced by some neuroleptics and those observed with TIQ and its homologs suggests that the latter may be a new class of short-acting neuroleptics.

Alignment layers for improved surface-stabilized ferroelectric liquid-crystal devices.

Ultrathin silane monolayer and silicon oxide alignment layers in surface-stabilized ferroelectric liquidcrystal devices are shown to enhance bistability and reduce degradation from ions.

Continuously tunable smectic A(*) liquid-crystal color filter.

A new continuously tunable color filter, which uses smectic A(*) liquid-crystal half-wave plates, is described and experimentally demonstrated. Multiple-stage Lyot filters with broad tunability and high finesse can be constructed with this design. The transmission characteristics of a single-stage filter, which is continuously tuned over 115 nm of the visible spectrum, are presented. Experimental results are compared with computer simulations, and they show excellent agreement. The advantages of the smectic A(*) liquid-crystal tunable filter over existing filter structures include low switching voltages (+/-30 V), rapid tunability (10 MHz), potentially high transmission, wide field of view, and large aperture.

Rapidly switchable optical filter for color generation.

A ferroelectric liquid-crystal (FLC) color filter is described and experimentally demonstrated. The device consists of three polarizers and five smectic C* FLC cells. With the application of an appropriate electric field to each FLC cell, five outputs are observed. These consist of the three primary colors (red, green, and blue) along with white and black. With the rapid addressing speed of the FLC's, the FLC color filter can be used for color display applications, such as backlighting FLC television.

High-speed analog achromatic intensity modulator.

We report what is to our knowledge the first implementation of a broadband analog intensity modulator composed of two chiral smectic liquid-crystal half-wave retarders. A reflection-mode intensity modulator employing a single active device has also demonstrated achromatic transmission. A quantitative theory for chromatic compensation is presented. By optimum selection of liquid-crystal retardance and orientation, intensity transmission is uniform throughout the visible. The chiral smectic liquid-crystal devices used in the implementation are capable of switching in less than 20 micros.

Applications of binary and analog hydrogenated amorphous silicon/ferroelectric liquid-crystal optically addressed spatial light modulators.

Analytical and experimental results that show novelty filtering, optical phase conjugation, and real-time edge enhancement by using optically addressed spatial light modulators that comprise amorphous silicon photodiodes and analog and binary ferroelectric liquid-crystal modulators are presented. The advantages of these devices for the above applications include high-speed, low-power operation and high spatial resolution.

Infrared linear diattenuation and birefringence spectra of ferroelectric liquid crystals.

Linear diattenuation and linear birefringence spectra of three ferroelectric liquid-crystalline materials, 764E, SCE4, and SCE9, are presented for the wavelength region from 2.5 to 12 microm. Relatively high birefringence (Deltan >/= 0.1) was found in the transmission bands from 2.5 to 3.2 microm and 3.6 to 5.7 microm, with only a small amount of interference from linear diattenuation (D

Second-harmonic generation in ferroelectric liquid crystals.

We present phase-matched, second-harmonic generation in the ferroelectric liquid-crystal material SCE9 (manufactured by BDH Ltd.). From the analysis of these results, the absolute values of all nonzero components of the d tensor have been obtained. A direct comparison between this material and the most efficient ferroelectric liquidcrystal material reported so far (ZLI3654) is made, which shows that SCE9 is four times more efficient at frequency doubling. At the phase-matching angle (theta = 19.1 degrees ) a d(eff) of 0.010(1) x 10(-12) m/V is measured. The results are consistent with near uniaxiality, the extent of which has been determined from experimental data (n(y) - n(x) = 0.0003, n(2) - n(x) = 0.17).