Comparison of retinal image quality with spherical and customized aspheric intraocular lenses

We hypothesize that an intraocular lens (IOL) with higher-order aspheric surfaces customized for an individual eye provides improved retinal image quality, despite the misalignments that accompany cataract surgery. To test this hypothesis, ray-tracing eye models were used to investigate 10 designs of mono-focal single lens IOLs with rotationally symmetric spherical, aspheric, and customized surfaces. Retinal image quality of pseudo-phakic eyes using these IOLs together with individual variations in ocular and IOL parameters, are evaluated using a Monte Carlo analysis. We conclude that customized lenses should give improved retinal image quality despite the random errors resulting from IOL insertion.     

Anti-bacterial protection of patients during rendering of specialized medical services

This paper surveys the available equipment and techniques to provide bacterial protection of out-patients given medical aid. It presents a classification of the medical equipment in terms of the design, spectrum of application and type of aid. It is emphasized that patients treated outside a hospital need bacterial protection. Methods for purifying and sterilizing the equipment as well as procedures for maintaining the preset environmental parameters are described. The paper outlines technical problems the solution of which may help the development and use of bacterial protection devices to be applied in special conditions.     

The serological examination of the population for leishmaniasis and the detection of Leishmania in rodents in the Republic of Guinea]

A serological study on leishmaniasis in human population of Guinea revealed the percentage of seropositive persons varying in different parts of the country from 0.84 to 4.76 (according to C-ELISA) and from 1.0 to 5.1 (according to IFAT). The majority of sera positively reacting in C-ELISA with the antigen of Leishmania major in dilutions of 1:800 and higher were received from Kundara District (northwestern part of the country), and with the antigen of L. donovani sensu lato from Sigiri and Kankan districts (northeastern part of the country). All the districts were situated in the savanna zone. The amastigotes of Leishmania were found in the liver and spleen of Tatera gambiana caught near Kindia. These data suggest the circulation of Leishmania over the territory of Guinea.     

The choice of the mode of operation of the XeCl-laser for angioplasty

The authors relate the results of studies carried out on an outfit model for laser angioplasty designed on the basis of exiplex laser. Optimal conditions for laser introduction into a quartz guide have been found. It is shown that the efficacy of interaction between XeCl-laser and tissue rises as the intensity of radiation increases. The energy of radiation at the guide outlet being 9 mJ, the resources of fiber work remained at a high level (greater than 10(4) impulses) whereas high velocity of tissue evaporation allowed elimination of an area 3 mm3 in volume during 1 minute, with the rate of impulse repetition amounting to 10 Hz.