Polarisation insensitive semiconductor optical amplifier withintegrated electroabsorption modulators

The authors demonstrate a 1.55 μm wavelength multiquantum well semiconductor optical amplifier, integrated with bulk layer electroabsorption modulators and passive waveguide beam expanders at the input and output ports. The device has a fibre to fibre gain of 9 dB, an extinction ratio of 15 dB per modulator, a spectral range >35 nm, and polarisation sensitivity <1 dB     

Irritancy testing in occupational dermatology: comparison between two quick tests and the acute irritation induced by sodium lauryl sulphate

OBJECTIVE: To evaluate the efficacy of exploratory vitrectomy for certain traumatized eyes with no light perception (NLP) and dense vitreous hemorrhage. METHOD: We performed vitrectomy on 10 patients with NLP eyes after ocular trauma. Of them, eight had open globe injuries and two had closed blunt ocular trauma. RESULTS: Postoperatively, six had visual acuities of light perception to 0.25 and four remained NLP. In most eyes, a potentially functional posterior retina and optic disc were observed during surgery. CONCLUSION: Dense vitreous hemorrhage could be the most important factor for NLP after severe ocular trauma. Therefore, NLP does not always mean permanent loss of vision. Proper primary repair of the wound and timely vitrectomy may give a chance of visual recovery in selected traumatized eyes.     

Thermally excited silicon oxide beam and bridge resonators in CMOStechnology

The design, fabrication, and characterization of thermally excited silicon oxide beam and bridge resonators by a modern industrial CMOS process combined with one additional maskless etching step is reported. The resonant frequencies, vibration amplitudes, and mode shapes of the devices are measured using a laser heterodyne interferometer. The acoustic transmitting and receiving sensitivities of the resonant structures in air are investigated in order to test their possible application as ultrasound transducers for proximity sensing. The experimental results are compared with finite element simulations using ANSYS     

Effect of titanium substitution on the structure and properties of Fe3Al-based intermetallic alloys

Substitutions (0–16 at%) of titanium for iron in Fe₃Al-based alloys rapidly solidified by chill-block melt-spinning stabilize the D0₃ and B2 ordered structures. Rapid solidification results in total suppression of D0₃ order in binary alloys, whereas alloys containing titanium have D0₃ structure. D0₃ and B2 antiphase domain size, lattice parameter and hardness increase with increasing titanium content of the alloy. The deformation mode changes from single (unit) bcc dislocation in binary alloys to two-fold superdislocation configuration in D0₃Fe₃Al-Ti alloys. Mechanical antiphase boundaries are generated by the movement of these imperfect configurations. All the alloys exhibited cleavage tensile failure. The mechanical properties are correlated with the observed structural changes.     

Growth structure investigation of MgF2 and NdF3 films grown by molecular beam deposition on CaF2(111) substrates

The growth structure of MgF₂ and NdF₃ films grown on polished CaF₂(111) substrates deposited by molecular beam deposition has been investigated using transmission electron microscopy (TEM) of microfractographical and surface replications as well as cross-sectional TEM, atomic force microscopy, packing density, and absorption measurements. It has been shown that by taking advantage of ultrahigh vacuum environments and a special stratification property of MgF₂ and NdF₃ films, the preparation of nanocrystalline films of high packing density and low optical absorption is possible at a substrate temperature of 425 K.     

Roxatidine versus ranitidine in the treatment of duodenal ulcer: a randomized, double blind, controlled, multicenter study in Thailand

BACKGROUND: Roxatidine acetate is a novel H2-receptor antagonist and several studies have shown that it is effective in healing duodenal ulcers. We evaluated the efficacy of roxatidine in a non-western society with particular different features and its healing of duodenal ulcers was compared in Thailand with that of ranitidine. METHOD: The design was controlled, randomized, double-blind, and multicenter. The study recruited a total of 215 patients who were endoscoped at the start of the trial and then randomized to receive a single capsule of roxatidine acetate, 150 mg, or an identical capsule containing ranitidine, 300 mg, both to be taken at night. Patients were evaluated at 1, 2, and 4 weeks, including endoscopy at the last session, as well as at 6 weeks with repeat endoscopy if the ulcer had not healed. RESULT: Both drugs relieved pain rapidly, usually within a week, and at repeat endoscopy at 4 weeks most ulcers (78%) were healed, 77.0 and 79.5 per cent in ranitidine and roxatidine, and in those patients in whom healing was not completed the healing rate had risen appreciably to 89.8 and 93.8 per cent respectively at 6 weeks. Small ulcers tended to heal quicker than larger ones, but smoking and alcohol intake had no negative effects on the results. CONCLUSION: The study was valid proof that roxatidine, in a single evening dose of 150 mg, was found to be both safe and effective in the rapid healing of duodenal ulcers when compared with 300 mg ranitidine.     

A capacitive threshold-logic gate

A dense and fast threshold-logic gate with a very high fan-in capacity is described. The gate performs sum-of-product and thresholding operations in an architecture comprising a poly-to-poly capacitor array and an inverter chain. The Boolean function performed by the gate is soft programmable. This is accomplished by adjusting the threshold with a dc voltage. Essentially, the operation is dynamic and thus, requires periodic reset. However, the gate can evaluate multiple input vectors in between two successive reset phases because evaluation is nondestructive. Asynchronous operation is, therefore, possible. The paper presents an electrical analysis of the gate, identifies its limitations, and describes a test chip containing four different gates of fan-in 30, 62, 127, and 255. Experimental results confirming proper functionality in all these gates are given, and applications in arithmetic and logic function blocks are described     

Acute bilateral amaurosis in sphenoid empyema caused by Streptococcus pneumoniae

PATIENT: A 14-year-old boy suffered from an acute bilateral blindness which occurred in 24-h time, accompanied by headache and raised temperature, with inconspicuous optic nerve head and fundus. After diagnosis of empyema with magnet resonance tomography (MRT) the sphenoid sinus was fenestrated and streptococcus pneumoniae isolated. Liquor and serology being inconspicuous, there was no evidence of leucaemic or autoimmune disease, intoxication or intracranial tumor. CLINICAL COURSE: The condition of the patient improved under systemic antibiotic therapy. The bilateral amaurosis remained and opticus atrophy developed. CONCLUSION: A bilateral amaurosis with descending opticus atrophy as a consequence of a sphenoiditis and spreading inflammation to the meninges and the optic nerve in the area of the chiasm is a rare event. The imaging technique of the MRT offers new opportunities for an early and more pointed diagnosis and therapy.