[Risk factors of adverse long-term consequences of tibial shaft fractures in children]. / Faktory riska neblagopriyatnykh otdalennykh posledstvii pereloma diafiza bol'shebertsovoi kosti u detei.

OBJECTIVE: To analyze leg length discrepancy and overgrowth after tibial shaft fractures in children. MATERIAL AND METHODS: We analyzed medical records of 103 patients younger 14 years old with tibial shaft fractures between January 2003 and November 2018. Treatment included plastering and insertion of titanium elastic nail. To identify the risk factors of leg length discrepancy ≥1 cm and overgrowth ≥1 cm, we performed logistic regression analysis. Statistical analysis was carried out using the SPSS software for Windows. RESULTS: Gender (p=0.014) and treatment methods (p=0.011) are the most significant predictors of leg length discrepancy and overgrowth. In boys, the risk of leg length discrepancy ≥1 cm was 7.4 times higher than in girls. The risk of leg length discrepancy ≥1 cm was 4.3 times higher after insertion of titanium elastic nail compared to plastering. The risk of overgrowth ≥1 cm was 5.4 times higher in boys than in girls. The risk of overgrowth ≥1 cm was 4.7 times higher after insertion of titanium elastic nail compared to plastering. CONCLUSION: One should consider the risk of leg length discrepancy and overgrowth in children with tibial shaft fractures. This is especially true for boys undergoing insertion of titanium elastic nail.

Electrical resistivity of polycrystalline graphene: effect of grain-boundary-induced strain fields.

We have revealed the decisive role of grain-boundary-induced strain fields in electron scattering in polycrystalline graphene. To this end, we have formulated the model based on Boltzmann transport theory which properly takes into account the microscopic structure of grain boundaries (GB) as a repeated sequence of heptagon-pentagon pairs. We show that at naturally low GB charges the strain field scattering dominates and leads to physically reasonable and, what is important, experimentally observable values of the electrical resistivity. It ranges from 0.1 to 10 k[Formula: see text] [Formula: see text] for different types of symmetric GBs with a size of 1 [Formula: see text]m and has a strong dependence on misorientation angle. For low-angle highly charged GBs, two scattering mechanisms may compete. The resistivity increases markedly with decreasing GB size and reaches values of 60 k[Formula: see text] [Formula: see text]m and more. It is also very sensitive to the presence of irregularities modeled by embedding of partial disclination dipoles. With significant distortion, we found an increase in resistance by more than an order of magnitude, which is directly related to the destruction of diffraction on the GB. Our findings may be of interest both in the interpretation of experimental data and in the design of electronic devices based on poly- and nanocrystalline graphene.

Heat capacity signature of frustrated trimerons in magnetite.

Recently it has been proposed that the long-range electronic order formed by trimerons in magnetite should be frustrated due to the great degeneracy of arrangements linking trimerons. This result has important consequences as charge ordering from the condensed minority band electrons leads to a complex 3D antiferro orbital order pattern. Further more, the corner sharing tetrahedra structure of spinel B-sites supports frustration for antiferromagnetic alignments. Therefore frustration due to competing interactions will itself induce disorder and very likely frustration in the spin orientations. Here we present very low temperature specific heat data that show two deviations to the magnons and phonons contributions, that we analyze in terms of Schottky-type anomalies. The first one is associated with the thermal activation across both ferroelastic twin and ferromagnetic anti-phase domains. The second Schottky-type anomaly displays an inverse (1/H) field dependence which is a direct indication of the disordered glassy network with macroscopically degenerated singular ground states.

Effect of Stone-Wales defects on the thermal conductivity of graphene.

The problem of phonon scattering by strain fields caused by Stone-Wales (SW) defects in graphene is studied in the framework of the deformation potential approach. An explicit form of the phonon mean free path due to phonon-SW scattering is obtained within the Born approximation. The mean free path demonstrates a specific q-dependence varying as q (-3) at low wavevectors and taking a constant value at large q. The thermal conductivity of graphene nanoribbons (GNRs) is calculated with the three-phonon umklapp, SW and rough edge scatterings taken into account. A pronounced decrease of the thermal conductivity due to SW defects is found at low temperatures whereas at room temperatures and above the phonon-phonon umklapp scattering becomes dominant. A comparison with the case of vacancy defects shows that they play more important role in the reduction of the thermal conductivity in GNRs over a wide temperature range.

[On the problem of permissible levels of emergency and subsequent occupational radiation exposure for people of reproductive age].

The results of studies of indices of reproductive function in 3 groups of males examined accordingly to an unified method: Group 1 - The staff of the Kalinin Nuclear Power Plant (KNPP) and the Smolensk Nuclear Power Plant (SNPP), who worked for liquidation of consequences of the accident (LCA) in 1986-87 at the Chernobyl Nuclear Power Plant (ChNPP), group 2 - the staff of the KNPP and the SNPP who did not work for LCA in ChNPP and the group 3 - the liquidators of the accident at ChNPP who were not included in the staff but are registered in the register of LPA participants in the Ryazan region are presented. The occurrence of congenital malformations (CM) and intrauterine growth retardation (IUGR) in infants, indices of unfavourable outcomes of pregnancy (UOP) in the families of males, describing the possible radiation-induced genetic effects in male germ cells was evaluated It was made a conclusion that the given in NRB-99/2009 constraints for emergency and subsequent occupational radiation exposures of males fail to provide protection from genetic effects in the offspring. The necessity to increase the duration of the protected reproductive period in males, on which there are extended restrictions for occupational and emergency radiation exposures from 30 years of age, as it is now accepted to the age of 35 years is demonstrated.

[Occupational exposure and the reproductive health of man--personnel of the producing department of Smolensk NPP].

A study of the reproductive health of man--personnel of the producing department of Smolensk NPP did not determine the influence of occupational exposure on the indices of child-bearing and on the prevalence of the sterility of men. At the same time focuses attention the fact of the generation of children in more than 30% men of older than 30 years, at the age, to which are not extended the additional requirements of the limitation of irradiation, or the fact of child-bearing in man--personnel with the accumulated doses more than 100 mSv, with which increases the risk of genetic effects in descendants.

Deterministic fractals: extracting additional information from small-angle scattering data.

The small-angle scattering curves of deterministic mass fractals are studied and analyzed in momentum space. In the fractal region, the curve I(q)q(D) is found to be log-periodic with good accuracy, and the period is equal to the scaling factor of the fractal. Here, D and I(q) are the fractal dimension and the scattering intensity, respectively. The number of periods of this curve coincides with the number of fractal iterations. We show that the log-periodicity of I(q)q(D) in the momentum space is related to the log-periodicity of the quantity g(r)r(3-D) in the real space, where g(r) is the pair distribution function. The minima and maxima positions of the scattering intensity are estimated explicitly by relating them to the pair distance distribution in real space. It is shown that the minima and maxima are damped with increasing polydispersity of the fractal sets; however, they remain quite pronounced even at sufficiently large values of polydispersity. A generalized self-similar Vicsek fractal with controllable fractal dimension is introduced, and its scattering properties are studied to illustrate the above findings. In contrast with the usual methods, the present analysis allows us to obtain not only the fractal dimension and the edges of the fractal region, but also the fractal iteration number, the scaling factor, and the number of structural units from which the fractal is composed.

[Autoimmune processes after long-term low-level exposure to electromagnetic fields (the results of an experiment). Part 5. Impact of the blood serum from rats exposed to low-level electromagnetic fields on pregnancy, foetus and offspring development of intact female rats].

This study evaluated possible adverse effects of injection of blood serum from rats exposed to microwaves at a power density of 500 microW/cm2 on pregnancy and foetal and offspring development in intact female rats. The study was performed with 59 pregnant Wistar rats. In utero mortality, embryo and foetal body weights and placenta weight were used for the evaluation of embryo and foetal development. Generally accepted integral and specific parameters were used for the evaluation of postnatal development of offspring during the first 30 days of life. It was shown that intra peritoneal injection of blood serum from IMF exposed rats (chronic 30-day RF exposure at 500 microW/cm2) to intact rats on the 10th day of pregnancy resulted in adverse effects on foetal and offspring development. Total mortality (in utero + postnatal) as well as delay in offspring development was higher in this group.

Electronic properties of disclinated flexible membrane beyond the inextensional limit: application to graphene.

A gauge-theory approach to describe Dirac fermions on a disclinated flexible membrane beyond the inextensional limit is formulated. The elastic membrane is considered as an embedding of a 2D surface into R(3). The disclination is incorporated through an SO(2) gauge vortex located at the origin, which results in a metric with a conical singularity. A smoothing of the conical singularity is accounted for by replacing a disclinated rigid plane membrane with a hyperboloid of near-zero curvature pierced at the tip by the SO(2) vortex. The embedding parameters are chosen to match the solution to the von Karman equations. A homogeneous part of that solution is shown to stabilize the theory. The modification of the Landau states and density of electronic states of the graphene membrane due to elasticity is discussed.

[Study of the effect of methylmercury and copper ions on primary photosynthesis processes in the green algae Chlamydomonas moevusii using the parameters of kinetic curves of the variable of chlorophyll fluorescence].

The effect of methylmercury and copper ions on the kinetics of light induction and dark relaxation of the variable of chlorophyll a fluorescence has been studied on cultures of the microalgae Chlamydomonas moevusii. It was shown that the toxicants added at concentrations that induce no decrease in photochemical activity of PS II (F(v)/F(M)) affect the electron transport on the acceptor side of PS II, the nonphotochemical quenching of excitation in the antenna, and the reoxidation of the quinone pool. At low concentrations, methylmercury produced a more toxic effect. The results obtained indicate that this approach can be used for detecting the changes in plant and algae cells at the early stages of the action of toxicants.

[Congenital malformations among offspring of the liquidators of the consequences from Chernobyl accident].

The frequency and the structure of congenital malformations at children of the liquidators of the consequences from Chernobyl accident, undergone to an external scale gamma-irradiation in dozes up to 25 cGy. In total is surveyed 2379 newborn at which is revealed 318 intrauterine development defects. The received results are compared to the earlier published data on birth of congenital malformations in families of the fathers who have undergone to an irradiation in connection with professional activity at the enterprises of a nuclear industry, with emergency irradiation, with irradiation as a result of explosions of nuclear bombs in Japan, and are discussed from positions of the basic rules (situations) of radiating genetics. Total frequency, the frequency of forms 21 of inherent defects of development, taken into account in the International register of congenital malformations and frequency 9 forms heaviest of congenital intrauterine development defects with the high contribution mutation components at children of the liquidators authentically is higher than on the average on Russian Federation. The dependence of the frequency congenital malformations at children from dozes of an irradiation of the fathers--liquidators is revealed. The curve of dependence of the frequency of congenital malformations from time, past after work up to copulation carries arched character with peak of rise of frequency of congenital malformations in 2-3 years and decrease in 6-7 years.

[Genetic effects in the liquidators of consequences of Chernobyl Nuclear Power Plant accident].

The purpose of the present research was the estimation of probable genetic consequences at the liquidators of the consequences of Chernobyl accident in 1986-1987. The research is made on two groups of the liquidators. The first group included the liquidators taking place on the account in the branch register and working now at the enterprises of a nuclear industry. The second group included 902 liquidators of consequences of Chernobyl accident in 1986 constantly living in the Ryazan area and which are taking place on permanent observation the account in regional hospital. For an estimation of probable genetic effects analyzed the data on frequency and outcomes pregnancy of the wives of the liquidators, on condition and on diseases of newborn, on switching intrauterine development defects (IDD). The analysis carried out depending on dozes of an irradiation: up to 5 cGy; 5-10 cGy and 10-25 cGy. Received materials testify, that at the liquidators, at a doze of an external irradiation 10-25 cGy, the determined effects--period long sterility, kept at a part them till 3 years come to light. The set of the received data, such as depending from the dose increase of frequency of spontaneous abortions and of inherent defects of development of newborn, the increase of frequency diseases of newborn and share newborn with low weight, allows to make a conclusion about an induction of genetic effects in sexual cells of the liquidators of consequences of Chernobyl accident at dozes of an external irradiation more than 10 cGy. Taking into account high biological efficiency of alpha-radiation (K = 20), and of beta-radiation (K = 2-4), the equivalent effective doze male gonads (testes) in 3-5 times is higher, than estimated only from external gamma-radiation.

[Combined effects of radiation and iodine deficiency on pregnancy and fetus].

The Chernobyl accident had combined effects of radiation and iodine deficiency (ID) on pregnancy. The establishment of a role of each of these factors in the genesis of comorbidity is of fundamental importance in the assessment of a radiation risk and in the development of goal-oriented preventive measures for reproductive health and antenatal development of an infant. The problem of impact of ID on fetal radiation damages is mainly that on radiation damages to the thyroid. The solution of this problem assumes particular topicality if radiation damages are due to the incorporation of radioactive iodine. The findings are indicative of the summation of thyroid abnormalities characteristic for each influencing factor. There is a more pronounced biological effect of radioactive iodine in the thyroid in ID.

[Phenotypical and molecular-genetic typing of salmonellae: reality and prospects].

The importance of the intraspecific typing of salmonellae for effective epidemiological analysis is shown. The methods (phenotypical and genotypical), used for the epidemiological marking of salmonellae, are characterized, their advantages and drawbacks, as well as prospects of their further use, are given. The importance of the standardization of molecular-genetic methods to ensure data exchange between different laboratories and the investigation of international outbreaks of enteric infections is pointed out. The international projects PulseNet and Salmgene of the surveillance of Salmonella infection, based on genotyping of Salmonella isolates, are presented.

[Adhesiveness and antibiotic resistance of the causative agents of salmonella infection in Gomel' region]. / Adhezivnost' i antibiotikorezistentnost' vozbuditelei sal'monelezov v Lomel'skoi oblasti.

The adhesive capacity, resistance to antibiotics and biological properties of Salmonella strains of different serogroups, circulating in the Gomel region, were under study. Resistance to antibiotics and changes in biological properties were accompanied by an increased adhesiveness of these strains. A high degree of adhesiveness was noted in S. hadar, a new for Belarus strains.

[Modifying influence of iodine deficiency on radiation damage to the fetus (review)]. / Modifitsiruiushchee vliianie iodnogo defitsita na radiatsionnye porazheniia ploda (obzor).

It known an oppressing action of radiation, including radioactive iodine isotopes on the reproductive system and fetus development. There are clinical data on a negative influence of iodine deficiency on the course of pregnancy and fetus development resulting from hormonal disfunction of thyroid gland and a mother-fetus system. There are no data about a character and mechanisms of interaction of radiation and iodine endemia at the combined action on the gonads and fetus. The urgency of this problem is caused by the fact that many regions of the country are characterized to some extent by iodine deficiency in local food and water (in Russian Federation such regions make approximately 50% of territories), and the opportunity of radiation accidents at nuclear plants with contamination of the environment with products of nuclear division (significant part of which is radioactive iodine isotopes is an objective reality. The analysis of a few published and own experimental data allows us to conclude that the combined influence of an external gamma-irradiation and iodine deficiency on reproductive function has a synergic character.

[Teratogenic effects of incorporated radionuclides]. / Teratogennye éffekty inkorporirovannykh radionuklidov.

Experimental data on teratogenic effects induced by incorporated alpha, beta and gamma-emitters were analyzed. It was found that the radioactive substances as well as external irradiation induced teratogenic effects. Teratogenesis caused by incorporated radionuclides has some peculiarities compared to the effect caused by fetus exposure to external radiation. These peculiarities are related to the fact of the limited penetration of incorporated radionuclides via placenta barrier so the radiation fetal doses are accumulated within long period of time and radiation dose rates are relatively low. The exposure to incorporated radionuclides does not induce severe developmental defects. Most frequent developmental defects of fetus include its death, general retardation of the development and growth. In such case the earlier pregnancy term was affected by radionuclide the more severe fetal damages occur in fetus because of the gradual increase of absorbed dose even in case of single intake of radionuclide. RBEs of radionuclides if compared to that for external gamma radiation are evaluated as follows: 2-4 (tritium oxide), 20 (241Am), 50 (238Pu) and 3-5 (131I in thyroid).

[The formation of absorbed doses of 137Cs in the body of the female and her progeny during suckling]. / Formirovanie pogloshchennykh doz ot 137Cs v organizme samki i potomstva v period molochnogo vskarmlivaniia.

The transfer of 137Cs with maternal milk to progeny was studied in rats. The rats were administered with 25 kBq/g of 137Cs nitrate (pH = 6) in a single oral dose immediately after delivery. Nonpregnant females served as control. Absorbed doses per activity unit to lactating rats were 23% lover than to nonlactating ones. Over the suckling period, absorbed doses to young rats amounted to about 35% of the absorbed dose to the nursing female. For nonlactating females, the internal dose approximately equalled the sum of doses to the nursing female and young rats.

[Kinetics of metabolism and mechanisms of formation of absorbed doses in the mouse testis from incorporated Cs-137]. / Kinetika obmena i zakonomernosti formirovaniia pogloshchennykh doz v semennikakh myshi ot inkorporirovannogo 137Cs.

The process of accumulation of absorbed doses from incorporated 137Cs in the body and gonads of male mice was investigated in our experiments. The radionuclide accumulated in gonads has very long time of excretion, and as result the radionuclide can be treated as long lasting and permanent source of alpha- and beta-radiation in gonads. The rates of total exposed doses in gonads were in 2.0-3.0 times higher then the average total exposed dose in hole body.