The Soil-Structure Interaction in Bridge Dynamics Problems

At the Bridges Department of Leningrad Institute of Railway Communication Engineers complex investigations of bridge dynamics under the seismic and rolling stock loads had been carried out. It is ascertained that for theoretical description of bridge oscillations the question of piers-base interaction is a matter of principal importance. During the process of oscillations there is a loss of energy due to the radiation by the propagation of elastic waves in the soil. These losses of energy considerably exceed the hysteresis ones, especially for bridges with metal span structures. Researches carried out allowed to make the theoretical estimation of the general factor of the span structure dynamics, to work out design technique for bridge piers and span structures under seismic loads (both according to the method of spectral analysis and with the use of the earthquake accelerograms), to predict the consequences of the local oscillations of bridge elements

Study of the Effect of Radiation Dose Rate on the Stability of Various Organochlorine Pesticides

Abstract irradiated at dose of 10 kGy with dose rate varied from 8.3 ⋅ 10−3 up to 2.33 Gy/sec. It is found that the shape of the degradation degree relationship on dose rate is similar for different OCPs in polar and non-polar solvents (hexane, 2-propanol) and does not depend on the concentration of initial substance. The maximum of the OCP degradation degree is registered in the dose rate range of 0.23-0.43 Gy/sec. A lognormal distribution is considered as a function best fitting the experimental data. The OCP degradation mechanism could be explained by the ratio of active and recombined particles along the gradient of ionizing radiation intensity. Keywords: organochlorinated pesticide; irradiation, dose and dose rate of gammaradiation; radiation degradation; functional dependenc

Genome-wide screening for genes whose deletions confer sensitivity to mutagenic purine base analogs in yeast

BACKGROUND: N-hydroxylated base analogs, such as 6-hydroxylaminopurine (HAP) and 2-amino-6-hydroxylaminopurine (AHA), are strong mutagens in various organisms due to their ambiguous base-pairing properties. The systems protecting cells from HAP and related noncanonical purines in Escherichia coli include specialized deoxyribonucleoside triphosphatase RdgB, DNA repair endonuclease V, and a molybdenum cofactor-dependent system. Fewer HAP-detoxification systems have been identified in yeast Saccharomyces cerevisiae and other eukaryotes. Cellular systems protecting from AHA are unknown. In the present study, we performed a genome-wide search for genes whose deletions confer sensitivity to HAP and AHA in yeast. RESULTS: We screened the library of yeast deletion mutants for sensitivity to the toxic and mutagenic action of HAP and AHA. We identified novel genes involved in the genetic control of base analogs sensitivity, including genes controlling purine metabolism, cytoskeleton organization, and amino acid metabolism. CONCLUSION: We developed a method for screening the yeast deletion library for sensitivity to the mutagenic and toxic action of base analogs and identified 16 novel genes controlling pathways of protection from HAP. Three of them also protect from AHA

ALTERATION OF ACTIVE SUBSTANCE CONTENT IN "HEXACHLORAN DUST" PESTICIDE FORMULATION AT EXPOSURE TO ELECTRON BEAM

The most popular methods of organochlorinated pesticides (OCP) destruction, which are based on thermal dechlorination, are not ecologically safe. The other process – radiation-chemical degradation – has got some advantages. It does not involve high temperatures and expensive reagents. In this study, the effective OCP degradation was observed under irradiation of residuals of the active substance of ‘Hexachloran dust’ pesticide formulation, intended for utilization. Parameters for the preparation powder (dry form) exposure to electron beam are discussed. It is shown that at the exposure to electron beam at dose of 100 kGy, the degradation degree of hexachlorocyclohexane (HCH) isomers in a composition of active substance achieves 56.2–66.3%

Replacement of the aortic valve, ascending aorta and arch in a patient with dextrocardia in the context of situs inversus totalis: a case report

The article discusses a rare case of successful replacement of the aortic valve, ascending  aorta and arch in a patient with dextrocardia  in the context  of situs inversus totalis. Situs inversus is a rare variant of normal anatomy  in which the major visceral organs are mirrored from their normal positions

Surgical treatment of cardiac echinococcosis: a case report

Echinococcosis refers is a chronic disease caused by tapeworms of the order Cyclophyllidea. Echinococcal cysts increase in size slowly and are often asymptomatic, and the symptoms of cardiac echinococcosis are nonspecific, which in turn can make diagnosis difficult. Early diagnosis and surgical treatment of this disease is crucial to prevent severe complications. Considering that the heart is affected extremely rarely, we want to demonstrate the successful surgical treatment

DYNAMICS MODEL OF THE CONTENT 131-I IN THE THYROID AND DAILY MILK YIELD IN DAIRY COWS

The model of radioiodine metabolism in the body of dairy cows, taking into account the content of stable iodine in the diet of animals, makes it possible to evaluate the effectiveness of the use of iodine preparations in order to reduce the accumulation of isotopes in the thyroid gland and milk

Toxicity assessment of natural waters from the Obninsk radioactive waste repository

The assessment of cyto- and genotoxicity of water samples from a regional radioactive waste repository using the Allium-test was carry out. Biotesting of natural waters from the site has demonstrated that negative biological effects are generated under the influence of water from well, located near the source of contamination. The percentage of aberrant cells in water samples from this well 4 is 2 times higher than in the control or other sources. Effects of water composition at the genome level are season independent. The Allium-test was shown to be highly sensitive and effective in testing a combined effect from radiation and chemical factors in field conditions