Optical transmission of nematic liquid crystal 5CB doped by single-walled and multi-walled carbon nanotubes.

Comparative studies of optical transmission of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), dispersed in nematic liquid crystal matrix 5CB, were carried out. The data evidence violations of Beer-Lambert-Bouguer (BLB) law both in cell thickness and concentration dependencies. The most striking is the fact that optical transmission dependencies for SWCNTs and MWCNTs were quite different in the nematic phase, but they were practically indistinguishable in the isotropic phase. Monte Carlo simulations of the impact of aggregation on direct transmission and violation of BLB law were also done. The results were discussed accounting for the tortuous shape of CNTs, their physical properties and aggregation, as well as strong impact of perturbations of the nematic 5CB structure inside coils and in the vicinity of CNT aggregates.

[Proliferative vitreoretinopathy: modern view on etiology and pathogenesis].

Studies on etiology and pathogenesis of proliferative vitreoretinopathy are necessitated by the absence of a unified theory, which would provide a clear understanding of causes and mechanisms of the disease. The results of recent investigations allow to consider proliferative vitreoretinopathy as an uncontrollable plastic process caused by certain changes in the retina aimed at survival of its cells under oxidative stress. This approach enables preclinical indication of the process and development of new therapies.

[Diabetic retinopathy in patients with type 1 diabetes mellitus].

The paper presents an up-to-date review of scientific data. Diabetes mellitus (DM), due to its epidemic prevalence and high occurrence of associated disability, is now one of the priority medical and social problems. Incapacitating manifestations of diabetes include visual impairment. Thus, diabetic retinopathy (DR), a late nonspecific vascular complication of DM, is the leading cause of blindness in the working-age population. The basic principle of DR treatment is optimal compensation of diabetes and concomitant conditions, such as arterial hypertension, nephropathy, and hyperlipidemia. Tight glycemic control is the main method for preventing and slowing the progression of preproliferative DR to later stages. Currently, the optimal and the most promising method of insulin injection to diabetes patients is insulin pump, as it enables accurate imitation of physiological secretion of insulin, provides the possibility of tight glycemic control, considerably decreases the risk for acute and late complications of diabetes, etc.

[Ocular hemodynamic in patients with diabetic retinopathy according to ultrasound dopplerography data].

Hemodynamic indices were estimated in ophthalmic artery, central retinal artery and short posterior ciliary artery using ultrasound dopplerography in patients with diabetic retinopathy receiving "Piyavit'". "Piyavit" improves hemodynamic indices in this patient group resulting in increasing of visual functions and reduction of macula edema height.

[Microcirculatory bed of bulbar conjunctiva and fundus oculi vessels in cervical osteochondrosis]. / Sostoianie mikrotsirkuliatornogo rusla bul'barnoi kon''iunktivy i sosudov glaznogo dna pri shenom osteokhondroze.

A total of 100 patients (200 eyes) with cervical osteochondrosis were examined. Microcirculatory bed of the bulbar conjunctiva, pressure in the central retinal artery, and diameter of vessels in the fundus oculi were assessed. All these parameters were disordered in the examinees in comparison with normal controls. The degree of changes inversely correlated with clinical manifestations of cervical osteochondrosis. Study of ocular hemodynamics in this patient population helps predict the time course of the underlying disease.