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The results of the production studies of professional groups of manual labor (stone saws, packers, slingers) are presented. It is shown that a change in the functional state of the body of workers leads to the development of fatigue and overstrain of the body systems of workers.

Carbon dioxide absorber based on hydrated zirconium oxide was synthesized with ammonium carbonate and hydrogen peroxide. The effect of the molar ratio between ammonium carbonate and hydrogen peroxide on the sorption characteristics of the absorber was examined. The structural-sorption properties of the absorber were analyzed. It was shown tat the absorber has a high absorption capacity for CO2.

Occupation-related and physiologic studies in workers using personal computers revealed variable degrees of changed visual performance in accordance with work conditions class and integral parameter of work intensity. Findings are that the performance change is caused by lower accomodation volume and decrease in temporary characteristics of clear vision stability. Correlation was established between work conditions class and percentage of the performance decrease during the working shift in videodisplay users.

There are presented the data of workers overstrain and fatigue conditions mechanisms based on physiological, psychological and ergonomic aspects of work processes in different types of activities (mental, visual-strained, physical). 15-year historical analysis, current state and prospects of labor physiology methods development are shown. Complex physiological and ergonomic investigations have allowed developing the measures of work ability raise and diseases prevention for workers various professions. Obtained results provided the basis of development of regulatory documents in area of human organism strain physiological norms, consequences of psycho-emotional stress and overstrain prevention taking into account working conditions class.

One of the most important tasks of occupational medicine is prevention of overexertion and occupational diseases in physical workers with various characters and degree of muscular exertion (local, regional and general). The studies demonstrated strong corellation between work conditions class in work hardiness, functional state and level of diseases development among 50 occupational groups examined. The article covers specific and differentiated measures on rational work and rest schedules, and other prophylactic means, with consideration of work conditions class for physical workers.

The functional status of the visual analyzer was studied in professional users of video display terminals (VDT) in relation to the type of displayed information. It was shown that irrespective of the type of displayed information, the VDT users developed visual fatigue over time. With unidirectional changes, visual fatigue was ascertained to be more pronounced and to have developed prematurely in users of VDT with alphanumeric information than in those of VDT with graphic information.

The authors demonstrated that incomplete consideration of ergonomic requirements in occupational process organization results in more intensive work and therefore to marked unfavorable changes in various human body systems. Preventing functional strain and lowering the occupational risk requires special measures implemented into daily work schedule and into activities of occupational rehabilitation centers.

The article tackles necessity of physiologic and ergonomic research in system of social and hygienic monitoring of workers' performance and health. A presented scheme covers physiologic and ergonimic aspects: monitoring of work process factors; monitoring of workers' performance and functional state. The authors formulated theoretic orientation of the problem and demonstrated scientific and practical importance of physiologic and ergonomic monitoring.

As the result of the study of stomatological status indices in children with gastroduodenal pathology associated with Helicobacter pylori it was established that caries incidence in children did not depend upon contamination while caries prevalence in examined children unlike caries incidence was associated with HP-status of the oral cavity. Patients with concomitant gastroduodenal pathology had frequently periodontal disease (PD). In children with chronic antral gastritis associated with Helicobacter pylori clinical manifestations were poor and tended towards inflammatory process chronicity. All the patients had chronic catarrhal gingivitis. In children with Helicobacter pylori associated pathology of GIT it proceeded with 100% contamination of gingival mucous membrane by Helicobacter pylori as shown by bacterioscopic study.

A saliva of the examined children of 3, 6, 12 years old with intensive caries are characterized by a changing of calcium homeostasis which is accompanied with redistribution of calcium fractions in a mixed nonstimulation saliva. In this case the concentration of Ca2+ is raisign considerably while the concentration of general calcium is raising slightly.

Complex descriptive, physiologic and hygienic studies covered various occupational groups of physical and mental work and revealed that health disorders probability depends on intensity of occupational factors. Increase in the intensity results in higher physiologic expenditure and greater incidence of occupational diseases. Symptoms of disorders appeared to depend on specificity of occupational factors.

Mapped phenotype of imperfect amelogenesis, type II imperfect dentinogenesis, hereditary opalescent dentin, Capdepont's dysplasia, and type II dentin dysplasia is described for the first time in Russia. Classification of hereditary disorders in dentin development is presented.

The authors demonstrated that work of female molders, acquisitors and stacking packers is characterized by physical load, great number of cliched manual movements, intensive inclinations of corpse and constrained working posture. Prolonged exposure to unfavorable occupational factors results in neuromuscular and cardiovascular stress that induces pathologic changes with increasing length of service. Complex of prophylactic measures suggested by the authors proves effective as releases working strain and delays fatigue during the working shift.

Nine patients with congenital deciduous and permanent adentia are described for the first time in Russia. Published reports are reviewed and recommendations on the DNA and prenatal diagnosis offered, which permit detecting women at a high risk of giving birth to handicapped children.

Ionized calcium and total content of all Ca fractions were measured in mixed saliva and blood serum of children aged 4 to 12 with solitary carious lesions or multiple caries. The level of ionized Ca was much higher in multiple caries than in individual lesions, and the content of bound Ca (protein-bound and in complex with other compounds) was decreased. The authors propose that recharging of salivary proteins caused by acidification of the saliva and dental deposit due to production of lactate and other organic acids is mainly responsible for redistribution of Ca fractions in mixed saliva. Ca release which results from demineralization of teeth, changed rate of salivary secretion and permeability of the blood-saliva barrier, and other factors may also contribute to redistribution of Ca fractions in the saliva, which plays an important role in the pathogenesis of caries.

The authors studied strain degree and fatigue severity in long-standing inconvenient postures at work of automobile loader operators. Those workers perform tasks in various postures due to the design of automobile loaders. Compared to standardized postures, long-standing inconvenient ones of automobile loader operators, characterized by left turn of corpse, appear to result in marked overstrain and significant fatigue of neuromuscular apparatus. If specific prophylaxis is absent, the work in such postures could induce considerable fatigue.

Physiological and clinical on-the-spot studies were performed of the labour conditions in 3 groups of female sewing-machine operators (respectively, engaged in making women's dresses, men's suits and men's coats). The analysis performed revealed different degrees of physical load and fatigue in the operators depending on the occupational peculiarities. Specific features of the peripheral nervous system and locomotor system disorders were studied in details, along with the causal relationships underlying the degree of physical load and fatiguability, overstrain development and cumulation. The results of the study were used as a basis for setting Health-Related regulations for sewing-machine operators.

The research data proposed proved the key role of the muscles' static tension in the process of fatiguability and strain growth in glass-work polishers' neuromuscular mechanisms. It was proved that a comparatively greater static load on the shoulder girdle muscles in glass-work polishers, as compared to crystal-polishers, results in more vivid pathologic changes in this professional group. The research served as a basis for a set of health-related measures, including both palliative and radical approaches.

The article provides data on the physiological value workload in lifting weights from different surface levels (the floor and working surface at the level of 0.7 m from the floor), at different rates and at the distance of 0.7 m. The results of the study proved that, in case of manual lifting of weights, the rate and the surface level are the most important factors accounting for the degree and the nature of the physiological reactions, e. i the physiological value of the workload. Manual lifting of weights from the working surface is marked by a lower physiological value of workload and higher efficiency. This should be taken into account in manual labour planning, workload and labour intensity evaluation, labour conditions and recreation improvement.

This article reports on the thermogravimetric investigation of mixtures of titanium no. 2 and carbon black with various mass carbon contents. Adding carbon black (as opposed to boron) to titanium leads to an increase in the rate of heat release of the oxidation reaction. An attempt is made to clarify the low-temperature oxidation mechanism of titanium mixtures in air. An x-ray phase and chemical (for bound carbon) analysis of specimens of a stoichiometric Ti + C mixture after heating in air to a temperature of 650/sup 0/C at the rate of 10/sup 0//min was conducted. The results indicate that the oxidation of the titanium-carbon mixture probably proceeds according to a more complex mechanism associated with the transport of the gaseous carbon oxidation products and their participation in the titanium oxidation.

The authors of this paper propose an approximate method of calculating one of the commonest measures of fire and explosion risk encountered in safety engineering practice: the minimum ignition energy of a layer of gaseous suspension of metal particles. This determination is also associated with the estimation of the critical mass particle concentration, above which, for a given value of the igniting pulse, the particle system ignites. It should be noted that it is correct to speak of the existence of three types of ignition concentration limits, associated with the autoignition of the system, the propagation of a flame, and focal ignition. Whereas in the first two cases the concentration limits are associated with the relation between the heat supplied by the exothermic oxidation reaction and the reaction's external heat losses, in the latter case the concentration limit also depends on the intensity of the igniting pulse.

The working conditions of the female workers engaged in industrial painting do not correspond to the optimal criteria and exceeds the permissible levels in some respects. Considerable muscle loads which cause the workers' fatigue and corporal pain lead to the overstain of the locomotor system. A complex of health improving measures is proposed to create more favorable labour conditions, lower fatiguability and promote prevention of locomotor system disorders.

Comparative data on the physiologic value of carrying over (along the horizontal surface with the rate of walking of 4.5 km/hr) and load lifting from the floor up to 0.7 m with the rate of 6, 10, 16 per min are given, the magnitude of external load with the weight of 4-300 H being different. Physiologic values of the completed work have been compared because of the significant difference in the work load when lifting and carrying over some objects. It is demonstrated that external load magnitude and physiologic value of muscular work are directly correlated. Physiologic work value during load lifting per work unit is higher than that during its carrying over. The ratio of physiologic value of load carrying over and lifting is different under various magnitudes of external load.