Characteristics of BENZOPYRAN Laser Dyes in Annealed Silica XEROGEL.

The spectroscopic and laser characteristics of two benzopyrane derivatives for 600-670 nm spectrum region of lasing in preliminarily annealed silica xerogel matrices in non-selective cavity under laser pumping at 551 nm have been measured and analysed. The influence of molecular structure of the dyes on their non-radiating losses has been revealed. The specific output laser energy of the studied matrices was approximately equal to the ones for corresponding methanol solutions under the same pumping conditions. The laser spectra of the matrices were displaced to the red region from the fluorescence maximum by about 1000-1500 cm-1 in a nonselective cavity. Such spectral displacement may improve the characteristics of biosensors made on the basis of these matrices because it shifts their emission spectrum to the range of deeper penetration into biological tissues.

[Problems and prospects of non-invasive screening for colorectal cancer].

High prevalence of colorectal cancer makes it a most serious socio-medical problem. Hence, the necessity of overall screening for prodromal changes and malignant neoplasms at the early stages of the disease. Despite a variety of efficacious instrumental diagnostic tools, the development of non-invasive screening techniques based on recent progress in understanding molecular mechanisms of carcinogenesis remains a highly topical issue. A pathogenetic model of colorectal cancer and pathophysiological basis of screening for colonic neoplasms are considered with the emphasis on the detection of tumour cells in faeces and their DNA carrying mutations in suppressor genes and oncogenes. Results of the studies with the use of one or several DNA oncomarkers are analysed in the context of their value for the diagnosis of colorectal neoplasms. High sensitivity and specificity of these methods make them very promising for application to the screening for colorectal cancer.

[Experimental study of root dentine permeability for medicines].

The use of contemporary endodontic methods of treatment do not always result in elimination of chronic nodus in periodontum, and filled teeth often remain potential noduses of infection, notwithstanding the impression of clinical and roentgenological wellness. Study of permeability of tooth root dentine under effect of medicines and microorganisms was done by means of introduction of colorant into the canal by iodine-electrophoresis method, observation of permeability of medicine from the canal through hard tissues of tooth and inhibition of growth of microorganisms in nutrient medium. It has been found out that the maximum permeability of tooth root dentine was observed in the cervical third of the root.

[The prevention and treatment of periodontal diseases in bronchial asthma patients undergoing a course of treatment in a hypoxic barochamber]. / Profilaktika i lechenie zabolevanii parodonta u bol'nykh bronkhial'noi astmoi, prokhodiashchikh kurs lecheniia v gipoksicheskoi barokamere.

The authors analyze the effects of hypoxia on clinical status and function of periodontal tissues in 71 asthmatics treated in a hypoxic chamber. Functional diagnosis methods were used in the study. The findings formed the basis for recommendations on the prevention and therapy of the shifts developing in the periodontium.