Human cerebral malaria: a pathological study.

The following report using light and electron microscopic and immunological techniques is based on a series of 19 Burmese patients who died of cerebral malaria. The principal change was blockage of cerebral capillaries by Plasmodium falciparum-infected erythrocytes. Ring hemorrhages and segmental necrosis of cerebral capillaries were common. Cerebral edema was variable in these cases. Electron-dense knobs, 40 X 80 nm in size, which protruded from the membrane of infected erythrocytes, formed focal junctions between endothelial cells and erythrocytes. These junctions resulted in the entrapment of erythrocytes and caused blockage in the capillary lumen. Immunoperoxidase study revealed that P. falciparum antigens and IgG deposits in the capillary basement membrane. This implies that damage to the cerebral capillary could be related to immune mechanisms.

Enhanced optical modulation using azo-dye polymers.

The performance of the conventional azo-dye polymer modulation system is compared with that of the recently developed attenuated-total-reflection (ATR) dye-polymer modulation techniques. Experiments based on Fabry-Perot resonance shifting in ATR geometry indicate that the modulation parameters, namely, speed, contrast, and efficiency, are enhanced. Although the dye-polymer response still remains fairly slow, ATR methods provide substantial improvement over the existing system. An all-optic long-range surface-plasmon azo-dye polymer modulation system is also proposed. Computer simulation of the reflectance and the photoinduced resonance shifting suggest that the proposed system can be used effectively for all-optic modulation. Some of the limitations of both systems and a pratical application of the ATR modulation methods are discussed.

Submicrometer lithography using lensless high-efficiency holographic systems.

A hologram recording geometry that was total internal reflection of the reference and reconstruction beams from a photosensitive material surface is used to achieve 0.5-microm resolution at lambda = 457 nm in the readout of a reconstructed image on a photoresist. Such a geometry has demonstrated stable image quality for parallel displacement within the illuminated area and diffraction efficiency tolerance within a +/-2 degrees tilt about the axis of the reconstruction beam. The total-internal-reflection recording system provides double-fringe sets for each plane component inside the volume hologram; therefore, a diffraction efficiency as high as 80% was observed. The result is applicable to highvolume submicrometer lithography and can be expanded to a 20-cm (8-in.) semiconductor submicrometer pattern. The use of a large-aperture, well-collimated laser beam provides us with much higher throughput than that of existing lithography machines.