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The laser-induced decay of an atomic system in an intense infrared and perturbative extreme ultraviolet (XUV) pulse is considered within Keldysh and streaking ionization channels. The streak camera method is discussed for two cases corresponding to different ranges of photoelectron momentum: i) the streaking channel significantly dominates the Keldysh channel and ii) the Keldysh channel of ionization is dominant, while two channels may interfere. The retrieval of XUV pulse parameters for these two cases is discussed and supported by numerical calculations.

The secondary generated radiation induced by orthogonal linearly polarized extreme ultraviolet (XUV) and infrared (IR) pulses is analyzed for the spectral region of the second XUV harmonic. The polarization-filtering-based method is utilized to separate two spectrally overlapping and competing channels, which are the XUV second harmonic generation (SHG) by IR-dressed atom and XUV-assisted recombination channel of high-order harmonic generation in the IR field [Phys. Rev. A98, 063433 (2018)10.1103/PhysRevA.98.063433]. We demonstrate the use of the separated XUV SHG channel for accurately retrieving the IR-pulse waveform and find the range of IR-pulse intensities for which this retrieving is applicable.

We propose to use the generation of even Brunel harmonics (BHs) by optical laser pulses for high-resolution gas-biased coherent detection of lower-frequency radiation in terahertz and mid-infrared ranges. BHs arise due to the acceleration of electrons liberated in the tunneling ionization process, and BHs pulses are much shorter than the laser ones. The latter makes it possible to significantly increase the temporal resolution of sampling detection compared to the use of cubic response of bound electrons generating the second harmonic of the gating pulse. However, as we show by solving the time-dependent Schrödinger equation for the helium atom, for an intense linearly polarized laser pulse, the atomic response contains a broadband noise signal that interferes with BHs and allows the detection of very high electric fields only. We show that the nature of this noise is related to the population of the Rydberg states of the atom, which can be effectively suppressed by using elliptical polarization of the gating pulse.

We analyze the polarization response of a single Ne atom in an intense infrared (IR) laser field and weak extreme ultraviolet (XUV) isolated attosecond pulse (IAP). The analysis is based on the numerical solution of the time-dependent Kohn-Sham equations and the recently developed perturbation theory in the XUV field for an atom subjected to an intense IR field. In our numerical results, we observe a significant increase in the magnitude of the atomic polarization response at the frequencies near the carrier frequency of the IAP and associate it with XUV-induced collective dynamics contributing to the polarizability of Ne. The specific interference between IR- and XUV-induced channels is discussed, and its utilization for retrieving the phase of the generated harmonics in the IR field is suggested.

An all-optical method is suggested for the metrology of an isolated, pulse-to-pulse stabilized attosecond pulse. It is shown analytically that high-order harmonic generation (HHG) yield for an intense IR pulse and time-delayed attosecond pulse keeps encoded waveform of the attopulse, which can be decoded by the time delay measurements of the HHG yield. The retrieval method is demonstrated by modeling HHG from Ne atom within time-dependent Kohn-Sham equations. The application of the suggested method for monitoring the carrier-envelope phase of the attosecond pulse is discussed.

Interpretation of strong-field phenomena is mostly based on the analysis of classical electron trajectories in an intense laser field, whose specific properties determine general features of nonlinear laser-matter interaction. Currently, the visualization of closed electron trajectories contributing to high harmonic generation (HHG) of the laser field is the prerogative of a theoretical analysis based on the time-frequency spectrogram of the induced dipole acceleration. Here, we propose a method for direct reconstruction of the HHG time-frequency spectrogram using a time-delayed probe XUV pulse. Our analytical theory and ab initio numerical simulations demonstrate that the XUV-assisted HHG yield as a function of time delay and harmonic energy mimics the short-time Fourier transform of the dipole acceleration induced by the laser field, thereby providing possible in-situ experimental access for tracing electron dynamics in strong-field phenomena.

We propose and investigate a method for generating tunable and phase-controllable mid- and far-infrared pulses in gas ionized by an intense two-color laser field composed of the chirped fundamental and its second-harmonic pulses with group time delay. The generation frequency equals the difference between the second-harmonic and the doubled fundamental frequencies and is continuously tunable by varying chirp or time delay. The duration of the generated pulses is determined by the ionization duration, which is much shorter than the ionizing pulse and is controlled by laser-pulse stretching or changing its intensity. Our quantum-mechanical calculations and analytical description show that this method can provide a wide tuning range spanning from several to more than a hundred THz using femtosecond lasers.

Described in the article is a clinical case report regarding successful surgical treatment of a female patient with total floating thrombosis of the inferior vena cava and thrombosis of the right atrium, complicated by pulmonary embolism. Our patient was a 42-year-old woman presenting with a clinical pattern of iliofemoral thrombosis. The examination revealed floating thrombosis of the inferior venal cava, right atrial thrombosis, and massive pulmonary embolism. Given the presence of absolute contraindications to systemic thrombolysis, it was decided to carry out surgical treatment by means of a hybrid-operation procedure. The woman underwent successful direct thrombectomy from the right-atrium cavity and branches of the pulmonary artery in conditions of artificial blood circulation, simultaneously accompanied by removing the floating thrombus from the inferior vena cava with the help of the 'Track' system, as well as by placement of a cava filter. Also presented herein is a review of the world experience gained in treating this pathology, followed by substantiation of using a hybrid approach for achieving an optimal clinical outcome.

We study control of high-order harmonic generation (HHG) driven by time-delayed, few-cycle ω and 2ω counterrotating mid-IR pulses. Our numerical and analytical study shows that the time delay between the two-color pulses allows control of the harmonic positions, both those allowed by angular momentum conservation and those seemingly forbidden by it. Moreover, the helicity of any particular harmonic is tunable from left to right circular without changing the driving pulse helicity. The highest HHG yield occurs for a time delay comparable to the fundamental period T=2π/ω.

There is still a great need for detection of biomarkers for early prediction and diagnosis of cardiovascular complications (CVC) in patients with CHD. Objective: To determine the role of MMP-1, 8, 9 in the risk of CCO in patients with CHD before and after coronary artery bypass grafting (CABG). Methods. The study included 75 patients with coronary heart disease before and after myocardial revascularization by CABG, including 40 men and 35 women aged from 45 to 74 years. Patients were divided into two groups: I group - 25 patients with CVC registered after CABG (acute myocardial infarction, ischemic stroke, pulmonary thromboembolism Branch); II group - 50 patients with coronary heart disease without complications after myocardial revascularization. Blood sampling was performed the day before surgery, on the 1st, 3rd and 10th days after CABG. Determining the level of MMP-1, 8, 9 in the serum was performed by ELISA using reagents specific «RD Diagnostics Inc.», USA. Results are expressed in ng/ml. Data are presented as medians and quartiles of two (Me, Q25, Q75). Within and between-group differences were evaluated using the Mann - Whitney, Spearman correlation coefficient and c2 test within the application program SPSS №16. Statistically significant differences between the indicators considered when you reject the hypothesis and significance level of p<0,05. Results. A statistically increased concentration of MMP-1 and MMP-8 in patients in group I. Undetermined significant dynamics of MMP-9 in patients after myocardial revascularization. Conclusion. The results indicate that the level of MMP-1, 2.5 ng/ml or more in patients with CAD is a diagnostic criterion for the risk of TE complications. No association between high content of MMP-8 and the presence of complications in patients after surgery. There were no significant dynamics of MMP-9 in patients after myocardial revascularization.

Ultrafast strong-field ionization is shown to be accompanied by atypical multiwave mixing with the number of mixed waves defined by the dependence of the ionization rate on the field strength. For two-color laser pulses of various frequency ratios, this results in the excitation of a free-electron current at laser combination frequencies and possibly in the excitation of the zero-frequency (residual) current responsible for terahertz (THz) generation in a formed plasma. The high-order nature of ionization-induced wave mixing may cause THz generation with uncommon laser frequency ratios (such as 2:3 and 3:4) to be virtually as effective as that with the commonly used frequency ratio of 1:2.

The study was performed with the help of a questionnaire of views of senior schoolchildren about the objectivity and stressfulness of various forms of the control of knowledge, the level of stress in the exams and measures for its reduction. 53.4% out of the students assess their knowledge in this area as insufficient. The most objective form of the control students consider an oral exam, the least stressful--blank testing. After passing the exams in class 9 we observed the evident reduction of representations of the objectivity of test forms of control. The necessity of the activization of educational work with students on the issues of prevention of exam stress and methodological work on perfection of the organization and content of the forms of Knowledge control is showed.

We investigate for the first time, both experimentally and theoretically, low-frequency terahertz (THz) emission from the ambient air ionized by a two-color femtosecond laser pulse containing, besides the fundamental-frequency main field, a weak additional field tunable near the frequency of the half harmonic. By controlling the mutual polarization and the powers of the main and additional fields, we determine the dependences of the THz power and polarization on the parameters of the two-color pulse. We also discover the resonantlike dependence of the THz yield on the frequency detuning of the additional field. The analytical formulas obtained using the model of the free-electron residual current density give an excellent agreement with the experimental results.

Environmental conditions in the area hosting a plant for processing and long storage of low- to moderately-active radioactive waste are described as reasonably safe. Residence in the area does not exert negative influence on the physical and mental development of children. Several indicators of physical development give better estimates than at the control territory. The difference can be accounted for by a better social situation in the study area (housing conditions, financial standing, food patterns, general lifestyle).

Along with the generation of extreme-ultraviolet and soft x-ray radiation, gas ionization by an intense few-cycle laser pulse can also induce the generation of low-frequency terahertz waves. The latter is caused by the excitation of a residual quasi-dc current in the produced plasma by the electric field of the laser pulse. We describe this phenomenon using the quantum-mechanical approach based on solving the 3D time-dependent Schrödinger equation. We calculate the dependences of the residual-current density on the carrier-envelope phase, duration, and intensity of the few-cycle laser pulse, and find optimal conditions for high-efficiency realization of the studied phenomenon.

Effect of lead fluoride dust on the micronuclear reticulocyte content in the bone marrow was shown. Some functional changes in the testicles and increase in the fetal death rate in exposure to 50 mg/m3 of lead fluoride dust were noted.

The article provides information on the hygienic assessment of the labour conditions in magnesium sulphate processing, along with the experimental data on the toxicity of this chemical compound at different ways of its penetration into human body, and describes the damaging mechanisms of its action. The toxicity parameters were related to the 4th class of hazardousness (GOST 12.1.007-76). The acute inhalational action threshold was determined at 112.7 mg/m3. The chemical substance did not exhibit any irritating action on the skin and mucosae, but was capable of penetrating through the undamaged skin and cause some functional disorders. The chronic inhalational action threshold was assessed at 10.2 mg/m3. Magnesium sulphate did not display any specific cardiotoxic or gonadotrophic action. MAC in the air in working zone areas was established at 2 mg/m3. Lesions of the liver were the major factor in the pathogenesis of intoxications.

Operations for aorto-coronary shunting and mammary-coronary shunting on a working heart were carried out without the use of a heart-lung machine in 19 patients with various forms of unstable angina pectoris in early periods (7 to 30 days) after the onset of the disease and in high left-ventricular end-diastolic pressure. There were no fatal outcomes. The post-operative follow-up periods ranged from 4 weeks to 2.5 years.

Variation of Actinomyces chromogenes var. trienicus 141-18 MSU, an organism producing trienin was studied under laboratory conditions. Nine stable spontaneous variants were isolated from the population of the initial culture when grown on Gause medium No. 1. The variants varied in differentiation and biosynthetic capacity, including such characteristics as size and form of the colonies, ability for formation of the aerial mycelium and its colour, capacity for sporulation, form of the spore chains and antibiotic production property. In the secondary structures the spores formed only in 6 variants out of 9 isolates. The spore form and spore membrane surface were close in all sporogenic variants, while there were significant differences in the structure of the sporophores. The variants forming the aerial mycelium of the same colour as that of the initial culture did not differ from it also by the nature of the spore chains (spirals with 3--8 turns). The variants with lighter aerial mycelium than that of the initial population formed straight sporophores or spirals with a small number of the turns (1--3). The comparative study of the antimicrobial spectrum of the variants and the component composition of the synthesized antibiotic complex showed that the asporogenic variants and dwarf variant signifcantly differed with respect to their phenotypes from the other cultures and had no antagonistic action. One of the assporogenic variants had only insignificant activity. All the spore forming variants did not differ from the initial culture in the complex of the antibiotics synthesized.

Polymorphism of the chromomycin-producing orgnaism Act. aburaviensis var. verrucosus 144--3 was studied. The stable variants differed in the morphologo-cultural properties, assimilation of the carbon sources, the component composition of the luminescence substances and the quantitative property of the antibiotic production. A substance with violet luminescence was found in the culture of varient I in addition to chromomycin. Similarity of the phenotypes observed in variants 1 and 2 when grown on complex organic media is explained by intensive chromomycin production by variant 1 on such media. Active colonies may be selected according to the colour due to chromomycin. Forms with an activity almost 4 times higher than that of the initial culture were found among the colonies of variant 2.

Some properties of the membrane proteins of Actinomyces sp. 26-115, i. e. its active variant and a variant not producing actinomycin C were studied comparatively. The membrane proteins of both variants of all ages tested represented a heterogenous fraction including about 30 protein components with a molecular mass of 17000 to 500000. There were differences in the protein component composition of the active and inactive variants. The membrane proteins of the active variant contained much more disulfide bonds than those of the inactive variant. It was shown in the model experiments on the protein binding of the phospholipid-lecithin membranes that the membrane proteins of the active variant bound higher amounts of lecithin during the whole developmental cycle than those of the inactive variant. It is suggested that the membrane proteins of the active variant had conformation differences as compared to those of the inactive variant.

Two natural variants, i.e. No. 1 and No. 2, not producing actinomycin were isolated from cultures of the actinomycin C-producing organism Actinomyces sp. 26-115. Variant No. 1 differed from the active variant by the growth dynamics and colony morphology. Variant No. 2 was close to the active variant by the growth dynamics. It was shown with electron microscopy that the cells of variant No. 1 differed from those of the active variant in the number and form of the mycelial septa, more even and compact structure of the cell walls and higher sensitivity to actinomycin. Still, they were more stable to the effect of lysozyme and ultrasound. The cell walls of the inactive variant No. 1 gradually lost teichoic acid during development, while the loss of peptidoglycan was observed only on transfer to the stationary phase. The cell walls of the active variant lost teichoic acid and peptidoglycan at the same time on transfer to the stationary phase. Peptidoglycans of both variants contained diaminopimelic acid (the configuration of which was not determined) and glycine (1:1) as differentiating amino acids. The two adjacent tetrapeptides were joined with one glycine radical. The peptidoglycan peptide chains of both variants contained muramic, glutamic and diaminopimelic acids and alanine (1:1:1:2). The peptidoglycans of the inactive variant No. 1 contained in addition valine and isoleucine. However, it is hardly probable that they are contained by the peptidoglycan peptide chains.

Trichothecium roseum Lk ex Fr produces simultaneously trichothecin and proteolytic enzymes possessing fibrinolytic, thrombolytic and esterase activity. In addition to the function of splitting and consuming the substrate, the proteolytic enzymes of T. roseum are probably able to hydrolize the other bond in the molecule of trichothecin, which results in partial inactivation of the antibiotic in both the fungus culture and the model experiment on trichothecin contact with the preparations of the proteolytic enzymes. Presence of proteases of T. roseum may be considered as a protective mechanism for detoxication of the metabolites toxic for the organism.

Relation between the growth of the heliomycin-producing organisms, biosynthesis of the antibiotic and morphological differentiation of the mycelium was studied. The curves of the culture growth were of diauxic nature. The synthesis of heliomycin was parallel to the organism active growth (trophophase). The antibiotic was synthesized in the germinating spores and localized in the areas of active growth and surface structures. The indicator properties of heliomycin were also evident in the organism mycelium. The antibiotic was registered in the young hyphae mainly in an oxidated form timed to the membrane structures. With the culture development heliomycin accumulated in the mycelium in reduced form together with lipids in the form of granules (vacuole structures). Condensation of heliomycin in the vacuoles (granules) started during the 2nd lag-phase, and may be associated with both heliomycin storing and inclusion of detoxication mechanisms. It was shown that heliomycin was consumed in the culture under conditions of starvation. In this case the antibiotic granules disappeared. The connection between the synthesis of heliomycin and the organism active growth, localization of the antibiotic in the areas of active growth, consumption of the antibiotic under conditions of starvation indicate that heliomycin is important for the organism and participates in the processes of growth and metabolism.

Ontogenesis of Trichothecium roseum during biosynthesis of trichothecin was studied during submerged cultivation on maize and synthetic media. Growth of the fungus is polycyclic; several generations of the submerged mycelium develop from the submerged conidia on the maize medium, and from the submerged conidia, chlamydospores and budding mycelium on the synthetic medium. Differentiation of the mycelium favours biosynthesis of the antibiotic. The nuclei in the cells of the submerged mycelium differ by their number, dimensions, and shape (round and elongated, polyploid). Several nuclei are found in the cells of the submerged mycelium more often during growth on the synthetic medium; this phenomenon is related to the reproductive cells -- submerged conidia and chlamydospores.

Neotelomycin induced lysis of the protoplasts of Bac. megaterium and inhibited their succinate dehydrogenase activity. Direct correlation between the lytic activity of the antibiotic and its effect on succinate dehydrogenase was found. Neotelomycin had no effect on the dehydrogenase activity of the protoplast lysates. Possibly, suppression of the protoplast succinate dehydrogenase of Bac. megaterium under the effect of neotelomycin was due to significant structural changes caused by the antibiotic in the protoplast membranes and leading to their lysis and not to the direct effect on the enzyme. Neotelomycin had practically no effect on the spheroplast dehydrogenase activity of E. coli resistant to the antibiotic and did not induce their lysis. Resistance of E. coli to neotelomycin must be associated not with the presence of the antibiotic non-permeable cell wall but the peculiar properties of the membrane cytoplasm.

In concentrations of 0.05-0.10 gamma/ml geliomycin suppresses inclusion of C14-uracyl into the acid-soluble fractions of the staphylococcal cells. Inclusion of C14-leucine at the same concentrations of the antibiotics was suppressed to a lesser extent. The above concentrations of geliomycin had practically no effect on inclusion of C14-thimine. Suppression of C14-uracyl inclusion was observed in 5 minutes of the cell incubation with the antibiotic, a significant decrease in C14-leucine inclusion being observed only in 30 minutes of the incubation. The effect of geliomycin on the staphylococcal cells within the concentrations inhibiting the microbial growth and suppressing inclusion of labeled uracyl and leucine into the cells was of the bacteriostatic nature. It was supposed that the antibacterial effect of geliomycin was based on suppression of RNA synthesis.

Two natural variants of the actinomycin C-producing organism Actinomyces sp-26-115, i.e. H1 and H2 differ in their sensitivity to exogenic actinomycin, colony morphology, growth dynamics on the synthetic medium and stability to ultrasound and lysozyme. Both variants synthesize no actinomycin. Variant H1 is sensitive to exogenic actinomycin, while variant H2 is resistant to it. Variants H1 and H2 have some similarity in the composition of membrane proteins. Still, they differ in the protein molecular masses, which are equal to 600000--500000, 220000, 130000. The active variant A and nonactive variant H2 have the most similar compositions of membrane proteins. These variants are also close in their growth dynamics, colony morphology, sensitivity to ultrasound and lysozyme. The membranes of all the variants studied contain phosphatidyl ethanol amide as the main phospholipid component. Insignificant differences are observed only with respect to the minor components. The content of teichoic acids in the cell walls of variant H2 is very high, slightly changes during the developmental stage and insignificantly increases on addition of actinomycin to the medium. The cell wall of variant H1 contains less amounts of teichoic acids. During the developmental stage they are liberated from the wall at a higher rate than peptidoglycan. The sensitivity to actinomycin does not increase with an increase in the culture age. It is probable that teichoic acid of the cell wall is one of the factors providing resistance to actinomycin in variant H2. It may be considered as a barrier preventing transport of exogenic actinomycin into the cell.

Actinomycin D0 differing from actinomycin D in replacement of I residue of sarcosine by glycine in one of the peptide chains was found to have a lower inhibitory effect on RNA synthesis in various biological systems. On interaction of E. coli with DNA actinomycin D0 formed a complex with DNA having the binding constant K=1.6 with 10-5 which was 100 times lower than the binding constant of actinomycin D. Therefore, actinomycin D0 formed a complex with DNA which was 100 times less stable than actinomycin D. Actinomycins D0, D and II having different conformations in buffer on interaction with DNA formed complexes having similar conformations. The conformational change from free actinomycin to bound actinomycin was found difficult in case of actinomycin D0 because of its slow rate of complex formation with DNA as compared to that of other actinomycins complex formation with DNA.

A new amino acid E was isolated from a mixture of the products of the reductive hydrolysis of ristomycin A 57% HJ in the presence of red phosphorus. Its characterization was performed. The new amino acid was formed as a result of reductive dehydration of the respective beta-oxyamino acid present in the native antibiotic and being completely destroyed during general acid or alkaline hydrolysis.

Heliomycin at a concentration of 100 mcg/ml had almost no effect on the growth of Escherichia coli, which was inhibited only upon the combined action of heliomycin and ethanol that facilitated the penetration of the antibiotic into the cell. Heliomycin inhibited in these conditions the synthesis of RNA and had no effect on the synthesis of DNA in the three studied strains of E. coli. The synthesis of protein either was not inhibited by heliomycin at all or was inhibited only to a small extent.

The biosynthesis of macrotetrolides by Actinomyces chrysomalus var. carotenoides was stimulated by acetic, succinic, propionic, oxalic, malic, tartaric, citric, pyruvic, alpha-ketoglutaric and fumaric acids. Incorporation of 14C-acetate into the molecule of the antibiotic and the data on dependence of the stimulating effect upon the quantitative ratio and time of the organic acid addition were indicative of the role of acetic, succinic and propionic acids as precursors of macrotetrolides. The other organic acids increased the biosynthesis of macrotetolides when added to the culture within wide time ranges of the culture development and prolonged the period of the mycelium productive state.

Heliomycin inhibited formation of the pool or purine and pyrimidine containing compounds in the cells of the growing cultures of Staphylococcus aureus and Escherichia coli both in the lag phase at the maximum rate of formation of the pool of compounds absorbing at 260 nm and in the exponential phase. A decrease in the concentration of purine and pyrimidine containing compounds in the acid-soluble fraction of the cells by the antibiotic was not caused by the disturbed permeability of the membranes. Apparently, heliomycin interfered with the regulation of RNA synthesis, either directly or through its action on the energy metabolism of the cells.

The chemical and physicochemical characteristics of one of the two inactive components, i.e. the reduced product of alkaline inactivation (PAH-II) of ristomycin. A were studied. The components formed on the antibiotic incubation in mild alkaline media: 0.05 M NaOH, 37 degrees C, 1.5-2 hours. It was shown that the retroaldol cleavage of the C alpha-C beta bond of the phenol serine fragment of the trinuclear dideschlorvancomycinic acid G at the aglycone N-end was one of the causes of ristomycin A rapid inactivation under such conditions.

Free intracellular valine in Actinomyces sp. 26-115 producing actinomycin C its functionally heterogenous. There are at least 2 pools of free valine. One of them supplies valine for protein biosynthesis and the second for the antibiotic biosynthesis. The volume of the pools is estimated. Inadequate reaction of the pools to similar effects is indicative of differences in their properties. The pool participating in protein biosynthesis strives for preservation of its volume. The pool participating in the antibiotic biosynthesis is capable of enlarging its volume to various levels depending on the change in the volume of the common intracellular pool.

Heliomycin inhibited synthesis of RNA in Staph. aureua which was clearly shown in the study of the antibiotic effect on RNA synthesis in the lag phase of the culture development: heliomycin markedly lowered the maximum RNA level in the biomass observed in the culture at the beginning of the exponential growth. On further growth of the culture heliomycin induced a significant retardness of the process of the natural decrease in the RNA biomass level resulting in increased content of RNA in the cells growing in the presence of heliomycin as compared to the control culture. Retarded natural decrease in the RNA biomass level in the presence of heliomycin was observed also on the antibiotic addition just at the beginning of the exponential growth, during the period of maximum RNA accumulation in the cells. Heliomycin had no effect on synthesis and biomass levels of DNA. Heliomycin inhibited the protein synthesis and was close to chloramphenicol by the level of inhibition of the summation protein synthesis in the biomass. However, comparison of the effect of the above antibiotics on synthesis of beta-galactosidase, an individual enzyme protein showed that heliomycin was much less active as an inhibitor of protein synthesis in comparison to chloramphenicol.