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2-Bromobenzaldehyde reacts diastereoselectively with chiral alkanolamines under carbon monoxide in the presence of a catalytic amount of bis(triphenylphosphine)palladium(II) chloride to afford the corresponding tricyclic isoindolinones in moderate to good yields.

2-Bromobenzaldehyde reacts diastereoselectively with chiral alkanolamines under carbon monoxide in the presence of a catalytic amount of bis(triphenylphosphine)palladium(II) chloride to afford the corresponding tricyclic isoindolinones in moderate to good yields.

Due to environmental and healthy concern, the allowable usage of lead will be decreased. The search of new lead-free solders with equivalent mechanical properties and microstructural stability to eutectic tin-lead (Sn-Pb) solder is an ongoing task. Solder joints in electronic products play not only a role to interconnect the electronic components but also to ensure the structural reliability of the electronic packages. As service temperatures for electronic assemblies are usually located in the high homologous temperature ranges (> 0.5Tm) of solder alloys, creep damage may take place. Therefore, a thorough understanding of the creep behavior of the newly developed lead-free solders is of extreme importance to the designers of electronic assemblies.

We report on the fabrication and characterization of broadband Bragg filters in microfabricated AlGaAs waveguides. Electron‐beam lithography and chemically assisted ion‐beam etching were used to fabricate first‐order gratings with 250 nm period. Bragg filters with rejection bandwidth ∼15 nm and centered at ∼1.6 μm are demonstrated.

We report all-optical switching with low-peak power in a microfabricated AlGaAs waveguide operating at 1.6 /spl mu/m. We show that by using a 1-/spl mu/m long microfabricated strongly-guided waveguide with 0.8 /spl mu/m by 0.9 /spl mu/m mode cross-sectional area, switching is achieved with an average power of 1.2 mW for 82-MHz mode-locked 430 fs pulses. The estimated peak pump power and pulse energy inside the microfabricated waveguide were /spl sim/30 W and /spl sim/14.6 pJ, respectively, which is 5-10 times lower than the values needed with conventional waveguides. In terms of a practicality index defined via switching power times waveguide length, this waveguide has around the best value. >

We report experimental results from an erbium‐doped gallium phosphide microdisk resonator pumped by a Ti‐sapphire laser at 980 nm. Fabrication and characterization of the microdisk resonator are discussed. Enhanced Er+3 intra‐4f‐shell photoluminescence was observed in the microdisk resonator due to microcavity effect and compared to a thin film sample. At low pumping power intensity, the photoluminescence from erbium‐doped gallium phosphide microdisks is an order stronger than that from a thin film sample.

We report our experiment on the use of a double‐disk structure to couple light output from a microdisk laser which allows us to maintain a high Q value of the microdisk resonator. The small photon leakage rate from the lower lasing disk to the top waveguiding disk can be carefully controlled by choosing the distance between the two disks. Various structures can be fabricated on the top disk to couple the light out. In this letter, a simple opening in the top disk is used for output coupling.

The fabrication and optical properties of an erbium-doped gallium phosphide microdisk resonator pumped by a Ti-sapphire laser at 980 nm were investigated. Enhanced Er3+ intra-4f-shell photoluminescence was observed in the microdisk resonator compared to a thin film, and is attributed to a microcavity effect. At low pumping power intensity, the photoluminescence from erbium-doped gallium phosphide microdisks is an order of magnitude more intense than that from a thin film sample.

This article describes the APACHE II classification system as a measure of severity of illness applied to AIDS patients with respiratory insufficiency. Among 82 patients, observed mortality in patients with high APACHE II scores (greater than 30) and those with low scores (less than 18) was significantly higher than predicted. There was variable correlation between predicted and observed mortality in the other APACHE II score ranges. The usefulness of the APACHE II scoring system is reviewed as limited and inaccurate in predicting survival rates in AIDS patients with respiratory failure.

We describe a novel pulse-delayed scheme to realize degenerate optical parametric amplification in chi((3)) planar waveguides. The scheme utilizes two identical birefringent plates placed before and after a chi((3)) planar waveguide to implement a single-arm, pulse-multiplexed nonlinear Mach-Zehnder interferometer. Using this scheme, we demonstrate ultrafast degenerate optical parametric amplification in AlGaAs waveguides.

An acrylic head appliance for the treatment of LeFort fractures is described. The appliance remains stable and effective during the course of treatment. When immobilization is no longer needed, it may be removed without anesthetizing the patient.

About 5% of the total adenylate kinase activity in the rat forebrain was found in a subcellular fraction enriched in synaptic plasma membrane (SPM). The enzyme remained membrane bound after washing by 1M potassium acetate. It was resistant to trypsin digestion under conditions which destroyed 90% of acetylcholinesterase activity. The SPM enzyme was solubilized by 0.25% Triton X-100 resulting in a 4-fold increase in activity. Similar effects were observed when SPM was treated with phospholipases, melittin and trifluoperazine. These results suggest the occurrence of an adenylate kinase closely associated with SPM the activity of which can only be fully expressed by disturbances to the hydrophobic lipid bilayer. The enzyme can be seen as strategically located to play a role in regenerating ATP required for the manifold activities of the synaptic membrane.