Search

In this paper, circuit and application aspects of different monostable–bistable transition logic elements (MOBILEs) are analysed. By taking advantage of the multi-state behaviour of resonant tunnelling devices (RTD) the logic depth and the circuit complexity per logic function is reduced at the gate level. Both, simulation and measurement results prove correct circuit operation in the gigahertz regime and I–O compatibiliy of the logic voltage levels. The scaling laws of the different MOBILEs are compared to each other in terms of speed and power dissipation. Detailed SPICE simulations based on experimental data precisely analyse the impact of fluctuations on the circuit functionality and performance. This study demonstrates that RTD-based MOBILEs are ready for use in digital circuitry such as linear threshold gates which offer a highly reduced circuit complexity. Copyright © 2003 John Wiley & Sons, Ltd.

The design and fabrication of linear threshold gates is presented based on a monostable-bistable transition logic element. Each of its input terminals consist of a resonant tunnelling diode merged with a transistor device experimentally realized in the InP materials system. Both, the heterostructure field effect transistor and the heterobipolar transistor approach are discussed in terms of level-compatibility, the facility of positive and negative weights, and robustness. The design and technology of a 1 bit full adder circuit capable of very low voltage operation (

In this paper the design and measurement results of RTBT monosatble-bistable transition logic element (MOBILE) gates are analyzed. By taking advantage from the multi-state behavior of resonant tunneling devices (RTD) the logic depth and the circuit complexity per logic function is reduced at the gate level. Due to the combination of a three terminal device (HBT) with the two terminal RTD the vertical RTBT has enhanced driving capabilites and is a promising candidate as a precursor for future nanoscaled ULSI circuits.

The response by 14 patients with open-angle glaucoma to treatment with carteolol 1% eye drops was investigated during a study lasting up to 15 months. Statistical analysis of the data revealed that carteolol had a highly significant IOP-lowering effect in all the patients studied. The mean decrease in IOP was as much as 41% of the initial value after the first day of treatment and after one week of treatment all the IOP values were close to 16-17 mm Hg. No long-term drift was noticed during the period of the study; no patient experienced any adverse reactions which could be related to the treatment with carteolol. This study therefore confirms the results of former investigations into the IOP-lowering effect of carteolol performed on Japanese subjects and classifies carteolol as a safe antiglaucoma agent which is also effective in Caucasian patients.

Topical administration of guanethidine leads to a "chemical postganglionic sympathectomy" that causes a hypersensitivity to epinephrine in the eye. Therefore, even low concentrations of epinephrine added to guanethidine lower intraocular pressure efficiently in cases of open-angle glaucoma. In order to test the feasibility of a therapy with both low dosages and minimal effective concentrations, at the same time avoiding the disadvantages of topical parasympathicomimetic treatment in normalizing intraocular pressure, a long-term study of ten patients presenting with confirmed open-angle glaucoma is being carried out. It has now been running for 15 months. A collyrium containing 1.0% guanethidine and 0.2% epinephrine is administered topically. The results and the statistical evaluation confirm a significant lowering of intraocular pressure without triggering any signs of tachyphylaxy during the whole duration of the trial. This represents a further alternative to nonmiotic treatment of open-angle glaucoma.

The nonsteroid anti-inflammatory drug (NSAID) diclofenac-sodium, in the galenic form of an eye drop solution (0.1%), has been tested in an open clinical trial in the following indications: episcleritis (30 patients), limbal corneal ulcer (9 patients), hay-fever conjunctivitis and/or conjunctivitis phlyctaenulosa (11 patients). The result of this clinical trial has shown that diclofenac-sodium eye drop solution fulfills all the requirements of a well-tolerated and effective NSAID. The application of diclofenac-sodium eye drop solution (3-5 times daily) resulted in a clear-cut reduction in the use of eye drops containing steroids and its prominent analgesic effect was impressive. Although a slight, transient burning sensation was noticed by a few patients shortly after instillation, no local or systemic adverse reactions were observed.

The response by 14 patients with open-angle glaucoma to treatment with carteolol 1% eye drops was investigated during a study lasting up to 15 months. Statistical analysis of the data revealed that carteolol had a highly significant IOP-lowering effect in all the patients studied. The mean decrease in IOP was as much as 41% of the initial value after the first day of treatment and after one week of treatment all the IOP values were close to 16-17 mm Hg. No long-term drift was noticed during the period of the study; no patient experienced any adverse reactions which could be related to the treatment with carteolol. This study therefore confirms the results of former investigations into the IOP-lowering effect of carteolol performed on Japanese subjects and classifies carteolol as a safe antiglaucoma agent which is also effective in Caucasian patients.

Topical administration of guanethidine leads to a "chemical postganglionic sympathectomy" that causes a hypersensitivity to epinephrine in the eye. Therefore, even low concentrations of epinephrine added to guanethidine lower intraocular pressure efficiently in cases of open-angle glaucoma. In order to test the feasibility of a therapy with both low dosages and minimal effective concentrations, at the same time avoiding the disadvantages of topical parasympathicomimetic treatment in normalizing intraocular pressure, a long-term study of ten patients presenting with confirmed open-angle glaucoma is being carried out. It has now been running for 15 months. A collyrium containing 1.0% guanethidine and 0.2% epinephrine is administered topically. The results and the statistical evaluation confirm a significant lowering of intraocular pressure without triggering any signs of tachyphylaxy during the whole duration of the trial. This represents a further alternative to nonmiotic treatment of open-angle glaucoma.