Attractive curves: the role of deformations in adhesion and friction on graphene.

Friction force microscopy measurements reveal a dramatic difference of a factor 3 between the friction forces experienced on single-monolayer graphene on top of oxidized and unoxidized copper substrates. We associate this difference with the strong and weak adhesion that the graphene experiences on these two substrates, respectively, but argue that it is too large to be ascribed either to a difference in contact area or to a difference in contact commensurability or even to a combination of these two effects. We use density functional theory to show a significant increase in the chemical reactivity of graphene when it is curved.

[Heterogeneity of chronic esophagitis in childhood].

Chronic esophagitis in children etiologically are heterogeneous. Was observed 83 patients aged from 3 to 17 years with histologically defined chronic esophagitis, 58 of them suffered from food and respiratory allergies. All children underwented endoscopy, morphological and immunohistochemical study of the esophagus biopsies with the definition IgE, IgA herpes simplex virus (HSV), cytomegalovirus (CMV) and Epstein - Barr virus (EBV) in the mucous membrane. The presence of chronic infection was established in 77 out of 83 (92.8%) children. All the patients underwented daily pH meters. GERD was diagnosed in 33 children. GERD was characterized by typical symptoms, combined with gastroduodenal pathology, usually Hp-associated, and increased gastric secretion. Morphologically at 15% of the patients with gastric metaplasia was found moderate inflammation. During examination of patients with allergic esophagitis was neither clinical nor explicit endoscopic manifestations, eosinophilic infiltration was observed in some patients, but inflammatory activity was lower than at GERD and infections. Esophagitis in chronic viral infections was characterized by a higher frequency of erosive changes, higher activity of inflammation. The combination of the three etiological factors were associated with more severe lesions of the esophagus.

[Association of the morphological features of gastric parietal cells with the concentration of H+/K+/ATPase autoantibodies in chronic gastrititis].

Chronic gastritis was morphologically verified in 119 patients. The count of parietal cells per 100 epitheliocytes of fundic glands was estimated. The sizes of parietal cells were measured by the morphometric computer program Videotest. For the diagnosis of autoimmune chronic gastritis (ACG), the level of antibodies to H+K+ATPase of gastric parietal cells in the patients' serum was determined by enzyme immunoassay. Childhood ACG has been found to be characterized by hyperplasia and structural changes of parietal cells with their preserved total count. The specific features of adult ACG include a significant reduction in the number of parietal cells, their sizes depending on the level of antiparietal autoantibodies, and marked ultrastructural changes as impairments in the differentiation and destruction of cytoplasm, organelles, and cell membrane.

[Chronic gastritis in children with concomitant diseases of the thyroid gland]. / Khronicheskii gastrit u detei s sopustvuiushchimi zabolevaniiami shchitovidnoi zhelezy.

We examined: 1 group--16 children with chronic gastritis (CG) and autoimmune thyroiditis (AT); 2 group--41 children with functional thyroidal pathologies; 3 group--23 children with CG only. The average age in all groups was 11.17 +/- 2.98. HP (68%) was revealed equally frequently in all the groups. Antibodies to H+/K(+)-ATPase of parietal cells were revealed in the first and second groups only (31-36%), p < 0.05 as compared to the third group. CG of the stomach body was more frequently revealed in the first group using endoscopic and histological tests. The second group had more frequent and more apparent lesions of the antral part. Thus, in case of concomitant diseases of the thyroid gland CG has an autoimmune nature of an inflammation of the mucous coat of the stomach.

[The role of intrauterine infection of the central nervous system with herpes simplex viruses in development of encephalopathies in infants]. / Znachenie vnutriutrobnogo infitsirovaniia tsentral'noi nervnoi systemy virusami prostogo gerpesa v razvitii éntsefalopatii u detei rannego vozrasta.

Intrauterine infections often affect the infant brain and cause meningoencephalitis and long-term encephalopathy. In this study we have analysed morphological changes in different parts of CNS of 22 deceased infants who had suffered from encephalopathy of different degree due to persistence of herpes simplex viruses. Morphological, immunofluorescent, serological methods were used. Antigens of herpes simplex viruses I and/or II were detected in the CNS of most examinees. Relevant antibodies were detected in the serum and cerebrospinal fluid. Intrauterine infection was confirmed by the presence of specific for herpes simplex viruses morphological changes in the placentas. Hydrocephaly, secondary microencephaly, false cysts, microgyria were found macroscopically. There were herpes simplex viruses specific histological changes such as nuclear hyperchromatosis, intranuclear basophilic and acidophilic inclusions and nonspecific changes (gliosis, productive vasculitis). The data demonstrate that intrauterine herpes simplex viruses persistence in the CNS is an important cause of infantile encephalopathy, specific and nonspecific changes indicate a chronic course of the infection and depend on the degree of clinical symptoms.

[Antibodies to H+/K+-ATPase of gastric parietal cells in children with Helicobacter pylori associated chronic gastritis]. / Antitela k H+/K+-ATFaze parietal'nykh kletok zheludka u detei s HP-assotsirovannym khronicheskim gastritom.

54 children at the age of 3-15 suffering from HP-associated CG were examined. Antibodies to H+/K(+)-ATPase of gastric parietal cells were determined with the help of the immune-enzyme analysis method. It was discovered that antibodies to H+/K(+)-ATPase are found in 27.7% of children. Concomitant autoimmune diseases, pangastritis, morphologic symptoms of the pre-atrophic stage of autoimmune gastritis as well as the drop of secretion at the fasting phase were discovered more often in antibody-positive patients. The successful eradication of HP in two children resulted in the disappearance of anti-parietal autoantibodies.

[Increase of probability of cell loss in the endothelium of blood vessel capillaries in progeny of rats after a low-dose irradiation of one of the parents (electron microscopy study)]. / Povyshenie veroiatnosti gibeli kletok v éndotelii krovenosnykh kapilliarov u potomkov krys posle oblucheniia odnogo iz roditelei v malykh dozakh (élektronno-mikroskopicheskoe issledovanie).

The total gamma-irradiation of Wistar rats at a dose of 0.25 Gy as well as at higher doses (0.5, 2 and 4.5 Gy) produces in the capillary endothelial cells of myocardium and lung a pronounced, dose-independent increase of the yield of necrotized cells. Similar changes were revealed in the animals, of which one of the parents (a male one day, a female seven days prior to copulation) was irradiated at doses of 0.25 and 0.5 Gy. This effect was observed in all studied descendants. The massive induction of the changes already by low radiation actions and their dose-independence allow considering the revealed effects as a manifestation of peculiar cellular reactions that presumably have epigenetic nature.

[Chronic and slow neuroinfections. Current status of problem]. / Sovremennoe sostoianie problemy khronicheskikh i medlennykh neiroinfektsii.

Some causes and conditions of chronic and slow neuroinfections were reviewed: brain immunological "priveledge"; congenital immunodeficiencies including clinically latent; immunomodulation induced by microorganisms due to infection of immune cells, inactivation of cytokines making difficulties to antibodies; disorders of genetic control of immune reaction; immunopathologic processes are of great importance for the agents persistence including autoimmunity. Microorganisms can locate in the neurons, glyocytes, endothelium. Neuroinfections chronic course depends on the agents properties and peculiarities of nervous system reactivity.

[Pathogenetic and morphological characteristics of acute inflammation of the central nervous system]. / Patogeneticheskie i morfologicheskie osobennosti ostrykh vospalitel'nykh protesessov v tsentral'noi nervnoi sisteme.

Virus, bacteria, mycoplasma, protozoa can be the causes of acute neuroinfections. The agents can penetrate into the brain by blood, nerve, lymphatic vessels, from the sinuses directly. Peculiarities of manifestations of acute neuroinfections depend on the agent tropism to receptors of nervous cell and specificity of brain immunoreactivity. The brain injuries can be induced by microorganism action or through immunopathologic processes. Dynamics of morphological changes in acute neuroinfections of different etiology are summarized. Histological, cytological, bacteriological, serological, immunofluorescent, histochemical methods are evaluated. Acute neuroinfection pathogenesis has many unresolved problems.

[Pseudomutagenesis. The persistent increase in the level of cellular variability induced by radiation and some other agents]. / K probleme psevdomutageneza. Persistiruiushchee povyshenie urovnia izmenchivosti kletok, indutsiruemoe radiatsiei i nekotorymi drugimi agentami.

Electron microscopic investigation of capillary endothelium cells in myocardium of irradiated rats revealed an unusual effect of persistent increase of probability of cell damage, similar in many relations to that described earlier for various unicellular species. New effect, unlike those traditionally studied, is characterised by non-stochastic nature, large number of the involved cells, reveals itself even after faint influences, and can be induced as well by agents other than radiation. The question is put on the probable commonness between these changes and the pseudomutagenesis which has the similar phenomenology.

[ Multigeneration carcinogenesis in the evaluation and prognosis of delayed radiation effects]. / Znachenie multigeneratsionnogo kantserogeneza v otsenke i prognoze otdalënnykh radiatsionnykh éffectov.

Radiation multigeneration carcinogenesis' mechanisms are associated with inheritance of non-specific genome lesions. Evidence indicates that the effect is significantly enhanced by some chemical carcinogens action on the offspring of irradiated parents. Hereditary character of the phenomenon is a prerequisite to accumulation of these genetic determinants in the population. The risk of radiation multigeneration carcinogenesis for man could be as much as 0.4 x 10(-2) Sv-1 over one generation.

[The radiation hygiene problems of multigenerational carcinogenesis]. / Radiatsionno-gigienicheskie problemy mul'tigeneratsionnogo kantserogeneza.

This review deals with a phenomenon of multigeneration carcinogenesis; the carcinogenic risk for offsprings of irradiated persons can be estimated as 4.10(-3) Sv-1. Though some epidemiological findings in this area are contradictory, multigeneration carcinogenesis may present a part of a population risk (genetic load). There is a need for recording the phenomenon in the normal ranges of radiation safety, i.e. to limit the planned irradiation of males aged 30-40 years, as well as females of the same age.