Chitosan Oligomer as a Raw Material for Obtaining Polyurethane Foams.

Decreasing oil extraction stimulates attempts to use biologically available sources to produce polyols, which are the basic components for obtaining polyurethane foams. Plants are inexhaustible source of oils, sugars, starches, and cellulose. Similar substrates to obtain polyols are chitosans.

Polyols and Polyurethane Foams Based on Water-Soluble Chitosan.

At present, majority of polyols used in the synthesis of polyurethane foams are of petrochemical origin. The decreasing availability of crude oil imposes the necessity to convert other naturally existing resources, such as plant oils, carbohydrates, starch, or cellulose, as substrates for polyols. Within these natural resources, chitosan is a promising candidate.

Bilateral choroidal melanoma--case analysis and literature review.

Uveal melanoma is the most common primary intraocular neoplasm in adults. Its bilateral localization is extremely rare. The aim of the paper is analysis of the cases of bilateral uveal melanoma.

[Abnormal pupils' reactions].

Examination of the pupils' light reaction and estimation of the pupils' diameter are the components of the routine physical examination of a patient. Disturbances in pupils' light reaction, unequal size of the pupils indicate damage of the nervous system and require careful diagnosis, both neurological and ophthalmological. Different aspects of anatomy, physiology and the most common pathological syndromes associated with disturbed pupils' light reaction and unequal diameters of the pupils were presented in the article.

[Cataract in an atopic dermatitis patient--case report and review of the literature].

Atopic cataract is one of several kinds of presenile cataracts, which develops in 20% of patients suffering from atopic dermatitis. Atopic cataract is the most frequently bilateral and characterized by fast progression. This type of cataract creates more and more important social problem, because of the young age of patients, who are usually professionally active and increasing incidence of atopic dermatitis in population.